Noise induced hearing loss test program,ear ringing for week,noise cancelling earbuds without music 107.7 - Review

18.10.2013
There is no point in an all-singing all-dancing testing service if the report you get means nothing to you. Additional detail for all referred individuals and all individuals where problems were identified, whether referred or not. One of the first choices any audiometry provider has to make is the equipment which is used to do the tests. In HSMC's case, we then also chose a style of unit which (almost uniquely as most models of audiometer don't feature this) as well as printing the individual's audiometry result in a large clear graph with the numerical values given below, it also gives the anticipated thresholds for someone of their age. As mentioned above, age is a critically important factor in audiometry as, along with unusual ear hair, a gut that just won't go and an inability to sit down in a chair without grunting, hearing is just one of those things that often gets worse as we plod along in life.
This audiometry chart shows the left ear to be good and above the warning levels while the results for the right ear are heavily reduced. This audiometry chart is a good example of the type of result in which we are interested in workplace audiometry.
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This medical discussion paper will be useful to those seeking general information about the medical issue involved. Each medical discussion paper is written by a recognized expert in the field, who has been recommended by the Tribunala€™s medical counsellors. A mixed hearing loss occurs when both a sensorineural and conductive hearing loss are present at the same time. According to the 1990 Noise and Hearing Loss Consensus Conference, a€?Noise Induced Hearing Loss (NIHL) results from damage to the ear from sounds of sufficient intensity and duration that a temporary or permanent sensorineural hearing loss is produced. PTS refers to a permanent loss of sensorineural hearing which is the direct result of irreparable injury to the organ of Corti.
The 4000 Hz a€?notcha€? or a€?dipa€? in sensorineural hearing has been a classic finding in NIHL over the years.
Why the 4000 Hz frequency appears more affected than other frequencies continues to generate some controversy. Individuals vary in their susceptibility to noise and the damage it may cause to the cochlea. Of interest, one universal finding is that on average hearing threshold levels (HTLs) in the right ear are better than the left ear by about 1dB. Whether one ear is more resilient to noise in the same individual (the so- called a€?tough vs. Please remember that when an asymmetric sensorineural hearing loss exists steps often need to be taken to exclude pathologic causes (i.e. The following statements tend to reflect what is agreed upon by the majority of scientists and physicians who deal with NIHL.
Noise induced hearing loss (NIHL) may produce a temporary threshold shift (TTS), permanent threshold shift (PTS) or a combination of both.
A PTS is caused by destruction of certain inner ear structures that cannot be replaced or repaired. The amount of hearing loss produced from a given noise exposure varies from person to person.
NIHL initially affects higher frequency hearing (3-6 kHz range, for nearly all occupational exposures) than those frequencies essential for communication (i.e. Daily noise exposure (8hrs) > 90 dB for over 5 years (or equivalent) causes varying degrees of hearing loss in susceptible individuals. NIHL is a decelerating process; the largest changes occur in the early years with progressively smaller changes in the later years (so-called Corso's theorem).
NIHL first affects hearing in the 3-6 kHz range, for nearly all occupational exposures; the lower frequencies are less affected. Once the exposure to noise is discontinued, there is no substantial further worsening of hearing as a result of noise unless other causes occur. Continuous noise exposure over the years is more damaging than interrupted exposure to noise which permits the ear to have a rest period.
The pathologic basis for presbycusis appears to be one of gradual devascularization of the cochlea and loss of functioning hair cells.
Clinically hearing loss from presbycusis appears to be an accelerating process unlike hearing loss in NIHL.
Unfortunately, there is no specific treatment available that will prevent age related hearing loss at present.
In the adjudication process of an occupational NIHL claim it is often difficult to separate the total amount of hearing loss from noise and age related change. For example, not everyone as they age will experience age-related presbycutic change (changes from presbycusis are variable with some individuals experiencing greater degrees of age related change than others). Moreover, exposure to high level noise early on may produce hearing loss more rapidly than aging such that the aging process has a negligible effect (i.e. The effects of noise exposure and aging on hearing when not combined are reasonably well-understood. Although it seems logical to a€?subtracta€? the age-related effects from the total hearing loss in order to quantitate the amount of hearing loss due to noise, this is really quite simplistic when one considers that aging effects and noise exposure effects can at times be practically indistinguishable for the most part audiometrically. Because compensation claims have required some consideration of presbycusis and its role in the total hearing loss of an individual various correction factors have been applied.
Dobiea€™s theorem states that the total hearing loss from noise and age are essentially additive (this is the theory put into practice when a standard correction factor for age after 60 years is applied in the Province of Ontario). Corsoa€™s theorem on the other hand states that any correction for age should be based on a variable ratio (as individuals age the assumption is that the effects of presbycusis variably accelerate by decade). Nevertheless the quantification of hearing loss attributable to age when occupational NIHL is present is really quite a complex phenomenon.
This is an inner ear disorder characterized by episodes of vertigo (an illusion of movement) lasting minutes to hours, fluctuating hearing loss and tinnitus (unwanted head noise).
Usually one ear is involved initially although over time the other ear becomes affected in nearly 50% of cases. Treatment is medical in most cases involving a low salt diet and diuretics and vestibular sedatives. Otosclerosis usually results in a conductive hearing loss from stapes footplate fixation due to new bone growth in this area. The diagnosis of cochlear otosclerosis is usually made when a family history of otosclerosis exists and other rare causes for a chronic progressive loss can be excluded. Although no medical treatment can ever reverse the sensorineural hearing loss, treatment with oral sodium fluoride may minimize and possibly stabilize an individuala€™s hearing.
Physical injury to the ear is usually the result of blunt trauma in the circumstances of a significant head injury. When physical trauma is severe enough to cause a temporal bone fracture (the temporal bone is the larger part of the skull bone that houses all the structures of the ear), two types of fractures occur; longitudinal and transverse. In general terms longitudinal fractures are much more common and tend to result in a fracture line through the roof of the middle ear and ear canal. Transverse fractures of the temporal bone occur when the fracture lines run directly through the hard bone of the otic capsule. Ototoxicity is defined as the tendency of certain substances to cause functional impairment and cellular damage to the tissues of the inner ear, especially to the cochlea and the vestibular apparatus. Aminoglycoside antibiotics are powerful weapons in the treatment of certain bacterial infections. Antimalarial drugs such as quinine and chloroquin unfortunately have ototoxicity as a side effect if taken in excess. This is a pathologic misnomer since this tumour is strictly a schwannoma of the vestibular nerve.
Although benign this tumour has serious health implications for the patient and is sought for by otolaryngologists when there is an undiagnosed asymmetry in the hearing.
This diagnosis is given to the individual who experiences a sudden hearing loss in one ear.
An individual's threshold hearing to pure tones at different frequencies (250 - 8000 Hz) is performed.
Air conduction (AC) thresholds are delivered via headphones and the individual is asked to respond to the sound of the lowest intensity (in dB) they hear at the frequency being tested. The pure tone audiogram forms the basis for assessing if an individual qualifies for Workplace Safety and Insurance Board (WSIB) benefits in the Province of Ontario. Complex words with equal emphasis on both syllables (so called spondaic words such as a€?hotdoga€?, a€?uptowna€?, a€?baseballa€? etc.) are given an individual at the lowest intensity they can hear. A list of phonetically balanced single syllable words (these are words commonly found in the English language in everyday speech such as a€?fata€?, a€?asa€?, a€?doora€? etc.) are presented to an individual at 40 dB above their speech reception threshold (SRT) in the ear being tested.
In this test a probe is placed into the ear canal that both emits a sound and can vary pressure within the canal which causes the ear drum to move. This tells whether the pressure in the middle ear is within normal limits and provides some indirect measurement of Eustachian tube function. Stiffening of the ear drum from loud noise occurs when the stapedius muscle contracts in the middle ear.
Absent stapedial reflexes are usually seen in middle ear pathology such as otitis media with effusion or otosclerosis.
If one measures how the ear drum moves when pressure is changed in the external ear canal from negative to positive a series of curves can be attained. The ability to measure minute electrical potentials following sound stimulation of the cochlea (i.e. Electrocochleography (ECoG) - This test measures electrical activity in the cochlea during the first 2 msec of cochlear stimulation.
Auditory Brainstem Response (ABR) - This term is synonymous with the term brainstem evoked potential (BEP) or the brainstem evoked response audiogram (BERA). Threshold Evoked Potentials (TEP) - These electrical waveforms are usually identified between 50 - 200 msec following cochlear stimulation and are thought to represent cortical pathways of electrical activity.
If AC thresholds are greater than BC thresholds this usually implies there is a conductive component to hearing loss from pathology involving the external or middle ear.
If BC thresholds are greater than AC thresholds this would typically suggest an exaggerated hearing loss or malingering. In its classic presentation a notched sensorineural hearing loss is noted at 4000 Hz that should be relatively symmetric.
Age related hearing loss typically presents with a bilateral symmetrical high frequency sensorineural hearing loss. There are often numerous discrepancies noted such as the presence of acoustic reflexes at levels below volunteered pure tone thresholds, discrepancies between volunteered pure tone average and speech reception thresholds etc. Subjective tinnitus can only be appreciated by the affected individual, is usually associated with a sensorineural hearing loss of some type and is the most common type noted.
Objective tinnitus, on the other hand, is quite rare but by definition is a noise that can be appreciated by an observer. Regardless of cause tinnitus can be quite disturbing for many individuals and can certainly affect their well-being. Treatment for tinnitus includes the use of more pleasurable competing background noise (i.e. The individual affected has undergone treatments to try to alleviate their perceived unwanted head noise (i.e.
Evidence to support a personality change or a sleep disorder as a result of the tinnitus. Hyperacusis is a curious phenomenon where an individual describes an uncomfortable, sometimes painful hypersensitivity to sounds that would be normally well tolerated in daily life. Treatment usually requires the gradual introduction of increasing sound intensity that becomes better tolerated with time. American Academy of Otolaryngology-Head and Neck Surgery Foundation Subcommittee on the Medical Aspects of Noise.
American Academy of Otolaryngology-Head and Neck Surgery Foundation: Guide for Conservation of Hearing in Noise.
Noise Induced Hearing Loss by Lonsbury-Martin BL, Martin GK and Telischi FF, Volume 4, Chapter 126 in Otolaryngology-Head and Neck Surgery 3rd Edition.
Permanent Impairment of Hearing - When any anatomic or functional abnormality produces a permanent reduced hearing sensitivity. Permanent Handicap for Hearing - The disadvantage imposed by an impairment sufficient to affect the individuala€™s efficiency in the activities of daily living (ADL). Permanent Disability - A person is permanently disabled or under permanent disability when the actual presumed ability to engage in gainful activity is reduced because of handicap and no appreciable improvement can be expected.
Acoustic Neuroma (Vestibular Schwannoma) - A benign brain tumour that arises on the vestibular nerve usually within the internal auditory canal (IAC).
Menierea€™s Disease - A classic inner ear disorder associated fluctuant sensorineural hearing loss, tinnitus and episodic attacks of vertigo lasting minutes-hours.
Otitis Media with Effusion - An encompassing term that describes the presence of fluid behind the TM.
Otosclerosis- Genetically inherited condition (approximately 1 in 20 people carry the otosclerosis gene) associated with the development of new, immature bone which primarily involves the stapes footplate leading to a progressive conductive hearing loss.
Tympanosclerosis - Calcification of the middle layer of the eardrum that looks like a patch of white chalk.
Mastoidectomy - Procedure designed to exteriorize disease in the mastoid air cells and adjoining middle ear. Ossiculoplasty - Procedure where the ossicular chain is repaired in order to try and improve hearing.
Tympanoplasty - When used in its most simplistic context it means the repair of a previous TM perforation.
Ventilation (myringotomy) Tube - The placement of an open ended tube or a€?grommeta€? into the TM acts like an artificial Eustachian tube which helps ventilate the middle ear space.
Decibel (dB) - A decibel is an accepted measure of sound pressure level used to describe sound intensity. Evoked Response Audiometry - Measures electrical responses within the inner ear, cochlear nerve and central nervous system that are generated by loud repetitive clicks.
This test is typically performed as one of the tests to confirm or exclude whether an exaggerated hearing loss (malingering) is present. Otoacoustic Emissions (OAEs) - Evoked test that measures minute responses to sound thought to arise from the contractile elements of the outer hair cells.
Recruitment - Perceived abnormal progressive loudness of noise in an individual with a sensorineural hearing loss.
Speech Discrimination Score (SDS) - The percentage score an individual correctly identifies when presented with a list of phonetically balanced (PB) words usually tested at 40dB above their hearing threshold.
Tympanometry - Formal tracing of how the TM moves when pressure is altered in the external auditory canal. Acoustic Trauma - Damage to the ear caused by a single exposure to an impulse nose of high density. Continuous Noise - A noise that remains relatively constant in sound level for at least 0.2 seconds.
Dosimeter - An instrument that integrates a function of constant varying sound pressure over a specified time period in such a manner that it directly indicates a noise dose and estimates the hazard of an entire exposure period.
Permanent Threshold Shift (PTS) - The permanent depression in hearing sensitivity resulting from exposure to noise at damaging intensities and durations.
Temporary Threshold Shift (TTS) - The temporary (usually several hours) depression in hearing sensitivity resulting from exposure to noise at damaging intensities and durations. Time Weighted Average (TWA) - The sound level or noise equivalent that, if constant over an eight hour day would result in the same exposure as the noise level in question (assuming a 5 dB doubling rule). The ear is a complex organ that has dual responsibility for hearing and balance (vestibular) function.
The ear canal (external auditory canal) originates from the concha (so-called bowl) of the auricle and extends medially to the tympanic membrane.
The ear canala€™s primary function is to provide a conduit for airborne sound waves to reach the tympanic membrane.
The middle ear cleft is a more extensive designation of the middle ear that has three main components which include the middle ear cavity, mastoid air cell system and the Eustachian tube. The mastoid air cell system consists of a series of small mucosal lined air cells interconnected with each other and the middle ear proper. Important structures of the middle ear include the tympanic membrane and the ossicular chain. The ossicular chain consists of the three small interconnected mobile bones known as the malleus (hammer), incus (anvil) and stapes (stirrup). The inner ear is the sensory end organ within the hardest bone of the body known as the petrous portion of the temporal bone. The cochlea specifically refers to the sensory portion of the inner ear responsible for hearing.
The vestibular portion of the inner ear consists of three fluid lined semicircular (superior, lateral and posterior) canals and the area called the vestibule which houses the otolithic macular endorgans. Sound vibrations are picked up by the pinna and transmitted down the external auditory canal where they strike the TM causing it to vibrate. When the mechanical vibrations of the stapes footplate reach the inner ear they create traveling waves in the cochlea.
Although the vast majority of the cochlear nerve fibres are termed afferent (ie nerves that carry electrical activity from the inner ear to the brain), within the cochlear nerve itself we have a small number of nerve fibres designated as efferent (nerves that carry electrical activity from the brain to the inner ear). Of interest when the outer hair cells become injured or affected by pathology they also lose their ability to a€?fine tunea€? the electrical responses arising from the inner ear. Although an individual may have apparently normal hearing it does not necessarily mean the cochlear nerve is undamaged. Sound is the propagation of pressure waves through a medium such as air and water for example. This is a very relevant question that is based on the definition of how hearing loss causes a handicap for the affected individual in their ability to identify spoken words or sentences under everyday conditions of normal living.
Although the higher frequencies are initially affected in NIHL an individual will really only begin to demonstrate a significant handicap to hearing to everyday speech in a quiet surrounding when the average of the hearing thresholds at 500, 1000, 2000 ( + 3000) Hz is above 25 dB. The inclusion of the 3000 Hz threshold value for NIHL awards is not always required depending on the jurisdiction. In the province of Ontario the Workplace Safety and Insurance Board (WSIB)a€™s Operational Policy Manual (OPM) Document No. A presbycusis (aging) correction factor of 0.5 dB is deducted from the measured hearing loss (averaged over the 500, 1000, 2000 and 3000 Hz frequencies) for every year the worker is over the age of 60 at the time of the audiogram. It is important to also appreciate that decisions can also be made on an exceptional basis which the WSIB has recognized.
Since individual susceptibility to noise varies, if the evidence of noise exposure does not meet the above exposure criteria, claims will be adjudicated on the real merits and justice of the case, having regard to the nature of the occupation, the extent of the exposure, and any other factors peculiar to the individual case.
A comprehensive list of US comparisons for NIHL and benefits can be found in Table 35.1 pages 797-799 in the Chapter concerning State and Federal Formulae Differences in Occupational Hearing Loss, 3rd Edition. It is likely that the two effects are not additive (Corsoa€™s theorem) but from a practical point of view this is how they are usually viewed with regards to compensation claims (Dobiea€™s theorem). At any given age for frequencies above 1000 Hz men will have more age related hearing loss than women.
Age related hearing loss affects all frequencies although the higher frequencies are usually more affected. Age related hearing loss is an accelerating process where the rate of change increases with age.
One can speculate that this might be one of the reasons an individual early on in their exposures may not be aware of a hearing loss, only to appreciate a hearing loss later in life when other factors such as presbycutic change occur. Although we think of presbycusis as an age related event not all individuals will develop this condition. Future genetic studies may provide us with further information concerning those at greater risk for progressive hearing loss from presbycusis in future.
A TTS is considered to represent a pathological metabolically induced fatigue of the hair cells or other structures within the Organ of Corti. In a PTS the destruction and eventual cochlear hair cell loss is thought to arise from direct mechanical destruction from high-intensity sound and from metabolic decompensation with subsequent degeneration of sensory elements. While one would normally expect full recovery of hearing function after a TTS there is one important consideration that needs to be taken into account.
The position in the world literature continues to support that any progressive hearing loss from acute trauma ceases unless the individual is re-exposed to more acute acoustic trauma or some other factor (s) occurs ( i.e. The classic studies of acute acoustic trauma by Segal et al (1988) and Kellerhals (1991) are often used to support this position. In the cohort study by Segal et al, 841 individuals from either the regular US army or military reserve sustained a permanent sensorineural hearing loss from acute acoustic trauma without subsequent re-exposure. The importance of the Segal study is that after 1 year one would not expect further worsening of hearing in subjects who ceased to have further noise exposure. Kellerhalsa€™ study reviewed a much smaller series of individuals who were exposed to acute acoustic trauma but looked at them over a 20 year duration. See related patient information handout on preventing noise-induced hearing loss, written by the author of this article. Noise-induced hearing loss is a sensorineural hearing deficit that begins at the higher frequencies (3,000 to 6,000 Hz) and develops gradually as a result of chronic exposure to excessive sound levels.1 Although the loss is typically symmetric, noise from such sources as firearms or sirens may produce an asymmetric loss. Epidemiological evaluation of hearing damage related to strongly amplified music (personal cassette players, discotheques, rock concerts): high definition audiometric survey on 1,364 subjects. Noise-induced hearing loss in young adults: the role of personal listening devices and other sources of leisure noise. Most musicians could be categorized as normal hearing, but their audiograms show notches at 6 kHz, a frequency that is associated with NIHL. Musicians show more noise induced hearing loss than could be expected on the basis of age and gender. IntroductionNoise induced hearing loss (NIHL) is caused by repeated exposure to loud sounds over an extended period of time, exposure to very loud impulse sound(s), or a combination of both.
MethodsParticipantsA total number of 245 musicians (490 ears) of five symphony orchestras participated in this study on a voluntary basis.
The specific subjective complaints of musicians in relation to objectively measurable facts. ResultsEffects in the pure-tone audiogramA vast majority of the musicians (92%) reported healthy ears. Flat loss (FL): audiograms which do not fall into the above mentioned categories, with no hearing thresholds exceeding 30dB at all measured frequencies.
Rest (R): all audiograms that do not match the characteristics of the above described categories.
ConclusionsIn summary, most musicians in this study could be classified as having normal hearing. AcknowledgmentsThe authors like to thank Miranda Neerings of the Academic Medical Center Amsterdam for her dedication and accuracy in testing the musicians and prof. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. ReferencesAnari M, Axelsson A, Eliasson A, Magnusson L (1999) Hypersensitivity to sound: questionnaire data, audiometry and classification. It has certainly given me some pointers on the training of these two topics to our staff and some helpful tips. A lot of our work is done for companies with no in-house speciality therefore we make sure all our reports contain information which is meaningful to a lay person. First and foremost is accuracy - its no good having something which wanders off in its own direction every few months. There is a faint red line visible on the audiogram above which simply put is the lower limit of acceptability and this changes with the age of the employee. A difference between the two ears such as this is a classic unilateral result for someone who has suffered accidental damage to one ear for example. The audiogram gives a good indication that the individual is suffering from a degree of noise induced hearing loss, (in this case, it is the graph of one of our technicians and was caused by a feckless studenthood spending far too long in noisy nighclubs!).
It is intended to provide a broad and general overview of a medical topic that is frequently considered in Tribunal appeals. Each author is asked to present a balanced view of the current medical knowledge on the topic. A vice-chair or panel may consider and rely on the medical information provided in the discussion paper, but the Tribunal is not bound by an opinion expressed in a discussion paper in any particular case.
This is the type of hearing loss that is found in routine unprotected daily exposure to loud noise potentially injurious to hearing in the occupational work force. This type of loss might be found in an individual, for example, with a large tympanic membrane (TM) perforation where mechanical vibrations along the ossicular chain are dampened.
For example an individual with a large TM perforation who received topical antibiotic ear drops for the treatment of a middle ear infection that caused inadvertent toxicity to the inner ear in addition (i.e. The hearing loss may range from mild to profound, may result in tinnitus (unwanted head noise) and is cumulative over a lifetimea€?. Noise induced deafness generally affects hearing between 3000-6000 Hz with maximal injury centering around 4000 Hz initially, an important point to remember.
There is good pathologic evidence however that demonstrates maximal cochlear hair cell loss in the tonal areas where the 4000 Hz hair cells normally reside in both animals and humans.
In susceptible individuals the early effects of presbycusis are occasionally seen around age 40. Secondary to hair cell loss one can often see progressive neuronal dropout along the cochlear nerve. In this regard the effects of aging in the absence of other factors cause a loss of hearing at all frequencies whose rate of growth becomes more rapid as age increased (especially after 60 years): an important point to remember in this context. To a large degree hearing loss with age is genetically primed; in other words the hearing your parents had as they aged is often passed on to you.
When the two processes are combined the resultant pathology and its effects upon hearing are not as well understood.
This certainly generates a more complicated mathematical model but probably more closely approaches what is happening physiologically. The hearing loss is typically a low-frequency sensorineural loss that fluctuates initially often reverting close to normal between attacks in the early stages. The presence of a pink-flamingo hue to the middle ear on otoscopy (so-called Schwartzea€™s sign), absent stapedial reflexes on audiometry and bone density changes involving the surrounding bone of the inner ear best appreciated on high-resolution CT scanning also helps in the diagnosis. Most patients suffering deafness by this mechanism will have had at least transient unconsciousness and have been admitted to hospital. A fracture through this bone (which is the hardest bone in the body) implies the force of the injury was severe and often incompatible with survival. Unfortunately these antibiotics can cause varying degrees of cochlear, vestibular and renal toxicity. The Auditory Brainstem Response (ABR) is used as a screening test while a gadolinium enhanced Magnetic Resonance Imaging (MRI) study is the gold standard investigation. The extent of the loss varies from a partial loss at one frequency right up to a profound loss at all frequencies with a profound discrimination loss. For the purposes of compensation, the most reliable audiograms will likely be performed by an audiologist who typically has a mastersa€™ degree or doctorate in audiology. The audiometer used to test hearing has been especially calibrated so that each frequency of sound tested for hearing has been normalized where 0 dB represents the lowest intensity of sound that the majority of people with normal hearing can hear from large population studies. When a conductive hearing loss is suspected the ear canal and inner ear mechanisms for transmission of sound energy to the inner ear are bypassed by placing a bone vibrator over the mastoid which directly stimulates the inner ear. A weighted pure tone average from frequencies at 500, 1000, 2000 and 3000 Hz is required for this determination from AC thresholds if a pure sensorineural hearing loss is present or from BC thresholds if any conductive element to hearing loss is present.
As a general rule the SRT value should roughly equal the pure tone average in the speech frequencies at 500, 1000 and 2000 Hz.
Most individuals with normal sensorineural hearing should get over 80% of the words correct at this level. Most individuals with normal sensorineural hearing will exhibit a reflex at 70-80 dB above their hearing threshold level at the frequency being tested.
When reflexes occur at less than a difference than 70-80 dB above hearing threshold at the frequency tested this is indirect evidence of a phenomenon called recruitment which is usually seen in cochlear pathology (i.e.
ECoGa€™s chief value lies in its ability to demonstrate wave 1 of the auditory brainstem response (ABR) and whether waveform morphology is suggestive of changes thought to occur in endolymphatic hydrops, the pathophysiologic substrate of MeniA?rea€™s disease. This test measures electrical waveforms obtained in the first 10 msec from cochlear stimulation. Middle ear pressures should be normal, stapedial reflexes present and a normal tympanogram noted.


In some instances it can be quite disabling for the affected individual who tends to withdraw from any exposure to uncomfortable noise. Cognitive behavioural therapy (CBT) has also demonstrated promise in a recent randomized controlled study.
The Relative Contributions of Occupational Noise and Aging in Individual Cases of Hearing Loss.
Specialized treatment based on cognitive behavior therapy versus usual care for tinnitus: a randomized controlled trial.
Diabetes and hearing impairment in the United States: Audiometric evidence from the National Health and Nutrition Examination Survey (1999-2004). The pathology is thought to arise from excess fluid in the inner ear leading to membrane ruptures (so-called endolymphatic hydrops). Certain antibiotics (especially the aminoglycoside class), antimalarials, chemotherapeutic agents and even excessive doses of ASA can be toxic to the inner ear. Although changes may take place as early as age 40, hearing loss due to aging usually starts to accelerate around ages 55-60 yrs and continues with age. Auditory Brainstem Response (ABR) - Synonymous with the term BERA (brainstem evoked response audiometry) or auditory BEPa€™s (brainstem evoked potentials).
Cortical Evoked Response Audiometry - Synonymous with Threshold Evoked Potential (TEP) testing.
Depending on the frequency of the sound certain parts of the cochlea will emit an a€?echoa€? in response. This occurs to a loud noise typically 70-80 dB above an individuala€™s hearing level at the frequency tested which causes stiffness of the ossicular chain and tympanic membrane Absent stapedial reflexes are usually seen in otosclerosis due to stapes footplate fixation for example. Conceptually it has three distinct anatomical components which include the external, middle and inner ear. The auricle is a flattened, funnel shaped appendage that contains a cartilage framework covered by skin. The anatomy favours the transmission of sound waves typically between 500-8,000 Hz which interestingly represents the common speech frequencies of most individuals. Proper function of the Eustachian tube which connects the middle ear cavity to the back of the nose (nasopharynx) is important for the normal middle ear aeration and function.
The tympanic membrane or ear drum is an ovoid, pale gray, semi-transparent membrane positioned obliquely at the medial end of the ear canal.
The tensor tympani and stapes muscles help stabilize the bones along with suspensory ligaments of connective tissue inside the middle ear.
Covered by an otic capsule its membranous portion (or labyrinth) contains a delicate system of fluid-filled canals lined with sensory neuroepithelium necessary for hearing and balance perception. It is a three chambered organ containing anatomical spaces known as the scala media, scala vestibuli and scala tympani. The scala vestibuli and scala tympani (T) by comparison contain fluid rich in sodium called perilymph. Within each semicircular canal is an area called the ampulla which contains hair cells sensitive to low frequency bidirectional fluid displacement that occurs with angular acceleration type movements of the head. The sound vibrations are then transmitted across the air-filled middle ear space by the 3 tiny linked bones of the ossciular chain: the malleus, incus and stapes .
The hair cells change these mechanical vibrations from the waves into electrochemical impulses that can interpreted by the central nervous system (CNS).
It can be a simple sound commonly known as a pure tone or it may be complex when we think of speech, music and noise. The prediction of a handicap did not appear to be improved by the inclusion of other frequencies > 4000 Hz.
What do other jurisdictions consider to be disabling hearing loss (provincial, national and international)?
The hearing loss that remains after the presbycusis adjustment is then used to determine entitlement to benefits.
It is generally thought that if an ear has suffered a permanent threshold shift from a noise induce etiology further noise exposure will cause less damage than would occur in a normal ear to a similar exposure. As previously noted the effects of noise exposure and aging on hearing when not combined are reasonably well understood. One however has to qualify this by saying that there is a significant amount of redundancy within the inner ear as it pertains to hearing.
Moreover we really dona€™t have a lot of good prospective longterm studies over 4-5 decades that can ultimately answer this question completely. Can moderate workplace noise exposure causing a TTS and repeated exposures later cause a PTS? Repeated noise exposure that causes a temporal threshold shift (TTS) can ultimately lead to a permanent threshold shift (PTS) with repeated exposures.
Some of this is based on the redundancy principle within the inner ear: not all hairs cells possibly recover following a TTS but enough do as to prevent hearing loss. Following acute acoustic trauma what is the natural history of the subsequent hearing loss?
Audiometric evaluations were performed on these individuals at 6 months, 1, 2 and 4 years after initial exposure. In his study cohort only 1% of individuals following acute acoustic trauma demonstrated deterioration of hearing of more than 20 dB in at least 1 frequency. Take a look at the following list to see which habits your should adopt to prevent or delay hearing loss. Exposure to Noise:     Noise-induced hearing loss is the most common yet preventable cause of hearing  loss. Diabetes:       The National Institute of Health (NIH) has found that hearing loss is twice as  common in people with diabetes. Cardiovascular disease:      Not only does exercise help to prevent type 2 diabetes, but cardiovascular  health and hearing health appear associated.
Noise-induced hearing loss is the second most common form of sensorineural hearing deficit, after presbycusis (age-related hearing loss). As many as 30 million Americans are exposed to potentially harmful sound levels in their workplaces.3 Outside of work, many persons pursue recreational activities that can produce harmful noise. When excessive, this force can lead to cellular metabolic overload, cell damage and cell death. Screening audiometry performed in the office revealed a 30-dB (mild) elevation of hearing thresholds at 4,000 Hz. An occupational hearing conservation program includes engineering and administrative controls to reduce noise exposures, employee training in the use of hearing protection and annual audiometry for all workers who are exposed to noise.Physicians providing occupational health services to a company may supervise the hearing conservation program, review abnormal audiograms and advise the program administrator. Holding a 512-Hz or 1,024-Hz vibrating tuning fork against the mastoid process, the physician asks the patient to indicate when the sound can no longer be heard. Audiologists can test a greater number of frequencies and can measure air and bone conduction to confirm whether the loss is sensorineural, conductive or mixed. By preventing noise-induced hearing loss, patients can reduce the impact of age-related changes on their hearing. Main questions are: (1) Should musicians be treated as a special group with regard to hearing, noise, and noise related hearing problems (2) Do patterns of hearing damage differ for different instrument types (3) Do OAE have an added value in the diagnosis of noise induced hearing loss (NIHL) in musicians.
A brief medical history and the subjective judgment of their hearing and hearing problems were assessed.
Musicians often complained about tinnitus and hyperacusis, while diplacusis was generally not reported as a problem. Other indicators, such as complaints and prevalence of tinnitus, complaints about hyperacusis and prevalence of diplacusis suggest that musiciansa€™ ears are at risk. Individuals of all ages, including children, adolescents, young adults, and older people, can develop NIHL, while exposed to intense sounds in the workplace, in recreational settings, or at home. Four of them were excluded from the analysis because the severe hearing losses reported in these ears could be attributed to aetiologies other than NIHL.
In analyses over instrument categories, percussion (PC) and other (OT) were not included as the number of musicians in these categories did not exceed 20.
Absolute pure-tone thresholds are, however, known to be strongly dependent on age and gender. For comparison between the results in these tests and the pure-tone thresholds, we used the average pure-tone thresholds of both ears.In the analysis of loudness perception, the focus was on the uncomfortable loudness level (UCL) and the dynamic range (DR).
A few musicians only wear hearing protection when strictly necessary and only in one ear (e.g.
When the subjective results on the question of diplacusis were compared to the results of the diplacusis matching, no significant correlation was found for any of the tested frequencies. Some musicians showed (almost) normal pure-tone thresholds with surprisingly low OAE responses, while others showed poor pure tone thresholds, but relatively high OAE responses.
Relative auditory thresholds were generally better than the normal-hearing reference group of ISO 7029 (2000) standard, except at 6 kHz, which clearly suggests an association with NIHL. Using the Extended Parallel Process Model to create and evaluate the effectiveness of brochures to reduce the risk for noise-induced hearing loss in college students.
According to the National Institute on Deafness and Other Communication Disorders, [1] nearly 15% of American Adults (26 million people) between the ages of 20 and 69 years may have suffered permanent hearing damage as a result of hazardous noise exposure. Noise-induced hearing loss in young adults: The role of personal listening devices and other sources of leisure noise. Estimated prevalence of noise-induced hearing threshold shifts among children ages 6 to 19 years of age: The third national health and nutrition survey, 1988-1994.
Trends in the prevalence of hearing loss among young adults entering an industrial workforce 1985 to 2004.
Perceptions about hearing protection and noise-induced hearing loss of attendees of rock concerts.
Noise induced hearing loss in dance music disc jockeys and an examination of sound levels in nightclubs. Output levels of commercially available portable compact disc players and the potential risk to hearing. The effects of listening environment and earphone style on preferred listening levels of normal hearing adults using an MP3 player. Evaluation of noise-induced hearing loss in young people using a web-based survey technique. Acceleration of age-related hearing loss by early noise exposure: Evidence of misspent youth. Intelligibility of conversational speech and clear speech in noise and reverberation for listeners with normal and impaired hearing.
Fear as motivator, fear as inhibitor: Using the extended parallel process model to explain fear appeal successes and failures. A radio-based approach to promoting gun safety: Process and outcome evaluation implications and insights.
Communicating cardiovascular disease risk due to elevated homocysteine levels: Using the EPPM to develop print materials. Increasing parent limits on novice young drivers: Cognitive mediation of the effect of persuasive messages. The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Using the EPPM to create and evaluate the effectiveness of brochures to increase the use of hearing loss protection in farmers and landscape workers. Using the Extended Parallel Process Model to prevent noise-induced hearing loss among coal miners in Appalachia. Perceived risk and efficacy beliefs as motivators of change: Use of the risk perception attitude (RPA) framework to understand health behaviors.
Bulimia interventions via interpersonal influence: The role of threat and efficacy in persuading bulimics to seek help. Motivating women and men to take protective action against rape: Examining direct and indirect persuasive fear appeals. An application of fear appeal messages to enhance the benefits of a jail encounter program for youthful offenders.
Alongside this, we always have an eye on the fact that reports may often be read by specialists therefore we also make sure that all the technical information they may need is also present. As we all know, when you've spoken to any specialist about anything vaguely medical they tell you what it all means and we sit there and nod meaningfully, then a week or a month later haven't got a clue what it was they were on about but remember them having a nice shiny pen in their pocket!
By having the dotted black and red lines on the chart we can give attendees a steady reference point and hopefully help them understand it that little bit better. This is classically evidenced by the dip seen at around the 4,000Hz level, followed by a recovery up to 8,000Hz. Occupational NIHL and presbycusis (degenerative hearing from aging change) represent the two most common causes of sensorineural hearing loss in society today.
For this reason workers ideally should be out of noise for at least 24 hours if not 48 hours prior to audiometric testing to avoid the effects of TTS on hearing.
Noise exposure from chipping machines and jackhammers characteristically damage the higher frequencies severely before affecting the lower frequencies. Nevertheless some individuals exposed to noise not infrequently demonstrate some asymmetry to their hearing loss.
The majority of changes histopathologically are noted in the basal turn of the cochlea where the high frequency hair cells and their corresponding cochlear nerve neurons are found. When the distended membranes rupture the resulting admixture of inner (endolymph) and outer (perilymph) fluids causes electrolyte disturbances (i.e. When the foci primarily affect the cochlea the patient may present with a chronic progressive sensorineural hearing loss in one or both ears.
As otosclerosis is a lifelong condition, the sensorineural hearing loss from cochlear otosclerosis is often superimposed on hearing loss from advancing age (i.e. The hearing loss noted is usually conductive and usually arises from discontinuity of the ossicular chain although any combination of conductive and sensorineural hearing loss can occur. If the individual survives there is usually complete loss of hearing and vestibular function on the involved side. Persistence of a conductive loss after the TM has healed would suggest continued problems with the ossicular chain. Careful and regular monitoring of auditory function (especially in the ultra high frequencies > 8000 Hz) and serum antibiotic levels may help the physician predict when ototoxic effects are occurring.
Pressure on or devascularization of the acoustic nerve or inner ear causes hearing loss, usually a high-frequency loss with reduced speech discrimination. Patients can sometimes identify the moment of occurrence or wake with it or appreciate it only when they go to use the phone.
If there is a significant discrepancy this could imply an exaggerated hearing loss is present as well.
When speech discrimination scores are especially poor this implies that there may be a lesion involving the cochlear nerve (i.e. In general terms if the Eustachian tube is functioning normally pressure on both sides of the ear drum should be similar (i.e. Waveform morphology is thought to arise from the cochlear nerve and the various relay stations in the brainstem the electrical response has to travel through.
The test is often indicated in an individual if there are concerns regarding an exaggerated hearing loss.
Tinnitus maskers are noise generators worn like a hearing aid that produces a sound of similar frequency to an individuala€™s tinnitus.
The problem with tinnitus however is that it is difficult to quantify objectivity and to fully appreciate how it affects an individuala€™s well-being. This test measure electrical activity along the cochlear nerve and at the various relay stations in the brainstem between 1-10 msec of stimulation. This test looks at electrical waveforms in the cortical areas of the brain between 50-200 msec after cochlear stimulation.
In humans the auricle has rudimentary functions for gathering sounds and in sound localization which is much more important in animals. The first part of the ear canal is cartilaginous and is lined by thick, hair bearing skin that contains numerous sebaceous and ceruminous glands. Malfunction of the Eustachian tube remains the leading cause for most middle ear disorders. The air cell system is typically underdeveloped or even absent (sclerotic) in individuals with a past history of recurrent ear disease. It is a three layered structure whose outer epithelial layer is contiguous with the skin of the external auditory canal, its middle layer is fibrous and its inner layer is composed of the same mucosal lining found throughout the middle ear cleft.
Clinically the malleus is attached by its handle to the tympanic membrane and is readily visible in most individuals on otoscopic examination. The separate but intimately related perilymphatic and endolymphatic compartments of the inner ear and their ionic constituents are efficiently controlled by the stria vascularis of the cochlea and the dark cells of the vestibular apparatus.
This ionic difference between these chambers forms the basis of the endocochlear electrical potential which is necessary for the conversion of mechanical activity from fluid movement within the cochlea to electrical activity arising from the hair cells. The hair cells of the otolithic endorgans (utricle and saccule) are covered by otoliths ( literally a€?little stonesa€? or crystals of calcium carbonate ).
The mechanical vibrations are transmitted to the inner ear via the vibrations of the stapes footplate. The tiny cilia (little hairs) on top of the hair cells (both inner and outer) are covered by a gelatinous membrane called the tectorial membrane. This apparent internal a€?feedback loopa€? is thought to be responsible for a€?fine tuninga€? by inhibiting some unwanted electrical impulses and by changing the mechanical properties of the basilar and tectorial membranes. Distortion of certain sounds arises when enough hair cells are damaged such that the hearing threshold is reduced. A cycle of a pure tone is represented by a sine wave appearance with an area of compression followed by rarefaction.
Low sounds tend to have a long wavelength relative to higher pitched sounds which have shorter wavelengths by comparison. Entitlement to health care and rehabilitation benefits is available when the adjusted hearing loss is at least 22.5 dB in each ear. When the two processes are combined, the resultant pathology and its effects upon aging are not as well understood.
In other words many hair cells in a similar region of the cochlea will produce a certain frequency response to sound stimulation. Upon saying this however we can actually demonstrate that many individuals will start to show early changes in hearing as early as age 40 years (in subjects screened to rule out other ear disease and noise exposure).
It is agreed that hearing loss and injury to the ear increases with the noise level, the duration of exposure, the number of exposures and the susceptibility of the individual.
The findings also indicate that the late progression of hearing loss following a single episode of acute acoustic trauma did not exist. Exposure to dangerous levels of noise can occur at work, home and in many  recreational activities.
This is a great idea to use for kids and gradkids when they are using your tablet or phone to play games and watch movies with their headphones on. Furthermore, of the 79 million adults with  pre-diabetes, the rate of hearing loss is 30 percent higher than in those with  normal blood sugar levels.
Cerumen cleans and lubricates the skin of the ear  canal and provides protection from bacteria, fungi, insects and water.  Attempting to remove cerumen or cleaning the ear canal with a cotton swab tends  to push earwax deeper into the ear canal. Shearing forces caused by any sound have an impact on the stereocilia of the hair cells of the basilar membrane of the cochlea; when excessive, these forces can cause cell death. Sixty million Americans own firearms, and many use them without adequate hearing protection.4 Other nonoccupational sources of noise include chain saws and other power tools, amplified music,5 and recreational vehicles such as snowmobiles and motorcycles.
The physician can clarify this test by performing the test on himself or herself, plugging one ear with a finger to simulate a conductive loss. At this point, the physician places the tuning fork in front of the auditory meatus to determine whether the sound can be heard again. They can also perform tests for speech discrimination and speech reception threshold.If a unilateral or asymmetric sensorineural loss, tinnitus, vertigo or other significant ear pathology is found, referral to an otolaryngologist is warranted. Hearing aids can amplify sounds but, despite technologic advances, often cannot fully correct problems of speech discrimination. Family physicians should educate and motivate patients of all ages to avoid potentially damaging noise, use hearing protection when necessary and seek treatment for an existing hearing deficit.
Musicians were subjected to an extensive audiological test battery, which contained testing of audiometric thresholds, loudness perception, diplacusis, tinnitus, speech perception in noise, and otoacoustic emissions. Tinnitus was most often localized utmost left and this could not be related to the instrument.
Continuing education about the risks of intensive sound exposure to musicians, with the emphasis on the possible development of tinnitus and hyperacusis and the need for good hearing protection is warranted. Among the working population who could be affected by NIHL, members of professional symphony orchestras are a specific group for two reasons: they are fully dependent on their hearing for their profession, and they are frequently exposed to loud music.
A direct comparison of the distribution of audiometric categories across instruments groups could only be done with some caution, as there were large variations in the number of musicians in the instrument subgroups. Therefore, we also calculated relative thresholds, corrected for gender and age effects according to ISO 7029 (2000) standards.
Table 2 shows the numbers and percentages of musicians with an interaural pitch difference of more than 1, 2, or 3%, respectively, and the numbers and percentages of musicians per instrument category that show diplacusis to such degrees. The pitch of the 4 kHz tone tended to be perceived lower in the ear with the poorest threshold. Tinnitus, diplacusis, and hyperacusis were found more often than could be expected in the general population, based on other studies. Festen for giving us the opportunity to use the speech-in-noise-test developed by the VU university medical center. By printing the anticipated age thresholds on the graph along with their result we get a nice clear point of reference for the attendee - 'this is where you are' and 'this is where we expect you to be'. Tribunal adjudicators recognize that It is always open to the parties to an appeal to rely on or to distinguish a medical discussion paper, and to challenge it with alternative evidence: see Kamara v. Constant or steady state noise by comparison remains relatively constant and lasts longer although fluctuations in sound intensity may occur.
This is however usually related to the fact that one ear receives a greater exposure to the noise than another.
Nevertheless the changes seen in presbycusis are typically non-specific and can also be seen in a vast number of pathologies including the effects of noise upon the inner ear. Occasionally both a low-frequency and a high-frequency loss occurs but not usually the type of high frequency loss seen following noise exposure.
When vertigo is incapacitating the balance function of the inner ear may be attenuated or ablated by the trans-tympanic instillation of gentamicin with relative preservation of hearing. If the footplate as well as the cochlea is involved then a mixed (conductive and sensorineural) loss might result. The pathognomic sign of a longitudinal temporal bone fracture is the so-called a€?step deformitya€? in the deep ear canal.
Facial paralysis from an injury to the facial nerve (a nerve that runs in close approximation to the inner ear) typically occurs.
The prolonged use of topical aminoglycoside antibiotics to treat middle ear pathology in the presence of a TM perforation is not without some risk which should always be kept in mind. In fact some people with a€?superhumana€? hearing can even hear sound intensities less than this relative value of sound pressure.
In complex situations (mixed hearing losses) it may also be necessary to a€?maska€? the ear not being tested (to prevent crossover of sound to the other ear).
When tinnitus is severe enough to affect an individuala€™s well-being a trial of pharmacological treatment is generally recommended.
Investigations such as a magnetic resonance imaging (MRI) are generally required to exclude the remote possibility of central nervous system pathology. Because of the brains proximity possible life-threatening complications can occur if left untreated (i.e. This test is typically performed when an asymmetric sensorineural hearing loss is present when there is concern a retrocochlear lesion such as an acoustic neuroma or MS might be present. The presence of waveforms following stimulation with the lowest intensity sound an individuala€™s cochlea hears provides us with a reasonable estimation of an individuala€™s hearing (usually within 5-10 dB of the anticipated threshold hearing at the frequency tested).
The deeper part of the ear canal is bony, lacks skin appendages and is lined by thinner skin densely adherent to the periosteal lining of the bone.
It is anatomically divided into 2 parts: the pars tensa and the pars flaccida (located in what is called the attic region of the tympanic membrane). Medially the arch (crura) of the stapes attaches to the inner ear via its footplate (which is a thin, flat oval piece of bone approximately 7mm X 3mm in dimension). Series of generation potentials culminate to form action potentials that transmit this electrical activity along the cochlear nerve fibres to the brainstem and onto the higher centers of auditory processing.
The hair cells of the vestibular macula respond primarily to gravity and linear accelerations.
The presence of active non-muscular contractile elements within the outer hair cells and their effects on movement of the basilar membrane is used to explain the concept of otoacoustic emission (OAE) testing.
When the sound gets loud enough the inability to a€?fine tunea€? sound becomes lost and more nearby hair cells are drawn into the firing needed to create an electrical signal; hence the distortion of a loud sound. Hair cell loss can continue until a certain critical point is breeched with the individual unaware of a hearing deficit.
Follow-up beyond the 1 year mark did not reveal any further deterioration of hearing in any individual. Moderate weight loss, eating healthy and exercise  can delay or prevent type 2 diabetes among adults at-risk for diabetes. Exposure to second-hand tobacco  smoke almost doubles the risk of hearing loss among adolescents.
Some types of toys for children can produce sounds capable of causing permanent hearing damage.6Noise can be described in terms of intensity (perceived as loudness) and frequency (perceived as pitch).
Concurrent exposure to ototoxic substances, such as solvents and heavy metals, may increase the damage potential of noise.7 Once exposure to damaging noise levels is discontinued, further significant progression of hearing loss stops.
In response to questioning, the girl reported spending several hours a day listening to music through head-phones. Normal hearing patients and patients with sensorineural hearing loss hear the sound longer through air than bone.
An aid should be carefully matched to the person's hearing deficit and lifestyle by a trained audiologist. Rabinowitz received his medical degree from the University of Washington, Seattle, and completed a residency in family medicine at Natividad Medical Center, Salinas, Calif. In 12 participants not all the tests were performed due to lack of time or because of technical problems in the equipment. Motorcycle drivers were requested to wear hearing protection during driving and be present at the lab at least half an hour before the tests would start. Eighty-nine (37%) indicated hearing problems in the family, mostly related to presbyacusis. However, when considering only the large groups, HS, LS, WW and BW, 40a€“52% of each of these groups fell into the audiogram category a€?Normal Hearinga€?.
At the 10th percentile, the 25th, the 50th, and the 75th percentile a large number of musicians score equal to or better than the ISO-population at all frequencies, except at 6 kHz where the distribution of thresholds is shifted relative to the ISO-population.
It can provide information about the sensitivity for loud sounds and in that sense it is related to hyperacusis. For a total of 106 musicians (44%) the interaural pitch difference was more than 1%, for 43 (18%) it was more than 2%, and for 20 (3%) more than 3% at one or more of the tested frequencies. Participants with an interaural difference of 1% or more at 1 and 2 kHz had significantly higher pure-tone thresholds [resp. HS, LS, WW, BW) showed only slight differences in the number of participants with tinnitus. Significant differences were also found between OAE of the normal hearing category and the other categories (i.e. Diplacusis does not seem to have much impact on the professional practice of the musicians, but tinnitus and hyperacusis can cause severe problems in professional and private environments. For example, truck drivers in North America not infrequently have a greater degree of hearing loss in their left ear (when the window is rolled down the left ear would be exposed to more sound from the engine). In the last resort the whole inner ear can be destroyed surgically by a procedure called a labyrinthectomy.
Exploration of the middle ear surgically with correction of the ossicular chain or insertion of a prosthesis is called an ossiculoplasty. On examination blood is usually seen in the middle ear behind the ear drum (a hemotympanum). The resultant hearing loss depending on the mechanism can be conductive, sensorineural or a combination thereof.


Of interest the first course of cisplatinum often demonstrates which patients are vulnerable to cochlear damage and what may happen in future if continued treatment courses are required. ANs are overwhelmingly unilateral, but in association with a rare genetic disorder, neurofibromatosis type 2, they may be bilateral. Another concept to appreciate is that the dB scale is a logarithmic (an exponentially increasing) rather than arithmetic (linear increasing) scale which makes it difficult to apply a percentage hearing loss to any individual.
Certain anti- depressants (especially the tricyclic or SSRI classes) and anti-convulsants (medications used for seizure control) have been effective for some individuals.
Mean comfort levels (MCLa€™s) and uncomfortable loudness levels (ULLa€™s) during audiometry provide some information concerning the threshold intensity of sound an individual can tolerate.
One general maxim in medicine is that a€?an unexplained unilateral sensorineural hearing loss should be considered an acoustic neuroma until proven otherwisea€?. Continuous migration of epithelium from the deeper to the lateral portion of the ear canal tends to keep the ear clean. The pars tensa or lower four-fifths of the ear drum is conically shaped and has a strong fibrous middle layer which provides strength. The blood supply to the incus can be tenuous compared to other structures of the middle ear. Abnormalities in vestibular end organ function often result in the patient experiencing the subjective complaint of vertigo. In general terms the greater the frequency the higher the pitch of the sound and the greater the intensity the louder we hear it. Of interest, in a parallel series of control patients who were further exposed to repeated episodes of acute acoustic trauma during the same study period by the end of 4 years 30% of these individuals had demonstrated significant hearing deterioration. Noise-induced hearing loss can be prevented by avoiding excessive noise and using hearing protection such as earplugs and earmuffs. Both the intensity and the duration of noise exposure determine the potential for damage to the hair cells of the inner ear.
The previous night, she had spent several hours at a rock concert without wearing hearing protection.
If hearing is symmetric, the patient perceives the sound in the middle of the forehead.FIGURE 4. Boasson also identified four factors that play an important role in the sound pressure levels in orchestra pits: the physical conditions of the orchestra pit, the orchestra arrangement, the repertoire, and the playing time. We decided to include all these participants into the analysis.Audiological testsParticipants were subjected to an extended audiological test battery containing tests on audiometric thresholds, loudness perception, diplacusis, tinnitus, speech perception in noise, and otoacoustic emissions.
Next the percentages of ears that were above the P90, P75, median, P25, and P10 percentile points were generated.
The 90th percentile of the musicians is placed beneath the 90th percentile of the ISO-population at all frequencies.
Tinnitus occurred the least in low string players, while it occurred more often in brass wind and high string players. It has been hypothesized that specific a€?musician characteristicsa€? are responsible for this result: wanted sounds such as music could be less harmful than unwanted sounds such as industrial noise (Karlsson et al. Depending on the intensity of the sound and the duration of the exposure, permanent sensorineural hearing loss and tinnitus (ringing in the ears) can ensue. Firstly, there is the comparison against the medical history of the person to see if there is a known reason for any observed losses. All things being equal most noise in industry however is a combination of primary continuous and superimposed impact type noise. Those who fire guns often demonstrate a greater degree of hearing loss in the ear closest to the barrel (the left ear in a right-handed shooter) because that ear would be closest to the explosion and the other ear would be protected by a a€?head shadowa€?. However the natural history is enigmatic with unpredictable periods of exacerbation and remission. For example the difference between 10 and 40 dB in sound pressure intensities is not a 4xa€™s increase but actually an increase by a factor of 1,000 or 103 in sound pressure intensities! An experienced tester, typically an audiologist, is required to perform these technically demanding tests. Wax and debris can collect in the ear canal when this migratory mechanism fails or is overloaded from infectious or inflammatory conditions. The pars flaccida or upper one-fifth is less distinct and has a poorly developed middle fibrous layer.
When pathology affects its blood supply it can lead to the erosion of its long process which is attached to the stapes.
In a conductive hearing loss, bone conduction becomes equal to or greater than air conduction. For many professional orchestras, the acoustical circumstances during practicing or performing are far from optimal with respect to avoiding, or at least minimizing the risks for hearing damage.NIHL is usually diagnosed by means of the pure-tone audiogram (PTA), the gold standard for identifying hearing threshold levels of individuals, enabling determination of the degree, type, and configuration of a hearing loss.
The figure clarifies that the distribution of hearing thresholds in musiciansa€”after a correction for age and gender is generally more favourable than would be expected on the basis of ISO 7029 (2000), except at 6 kHz, at which a higher percentage of the musicians scored below the ISO-percentile scores. Their UCLs ranged from 76 to 120 dB SPL and the average UCL values were slightly lower than could be expected on the basis of the UCLs at pure tones in a general population. No gender difference was found in the subjective rating.Effects in OAE-responsesOAE-responses were obtained from 479 ears. 1983), or musicians perform relatively good on pure-tone audiometry because of a strong motivation and familiarity with detecting pure tones (Dowling and Harwood 1986).The musicians participated on a voluntary basis.
Furthermore, to make a statement about the early diagnostic qualities of the otoacoustic emissions towards NIHL, there is a need for more data on the development of otoacoustic emissions over time. Secondly the results are compared against any previous audiometry to identify any changes which may have taken place.
This makes the pars flaccida especially susceptible to negative middle ear pressure and prone to retractions that can lead to the formation of retraction pockets. Another structure called Reissnera€™ s membrane (R) forms the roof of the scala media (M) which separates this from the scala vestibuli (V). In complex sounds the interaction of its pure tone components forms the basis of its complexity or its psychological counterpart known as timbre. When hearing loss is suspected, a thorough history, physical examination and audiometry should be performed.
Noise exposure measurements are often expressed as dB(A), a scale weighted toward sounds at higher frequencies, to which the human ear is more sensitive.
Otoacoustic emissions were more intense with better pure-tone thresholds, but due to large individual differences it can still not be used as an objective test for early detection of NIHL. Before testing the otoacoustic emissions, the participant had otoscopic inspection in order to check for cerumen. The level of the tinnitus was matched and compared with the audiometric threshold levels resulting in a sensation level of the matched tone (dB SL).
We are aware that this could have produced a selection bias, probably towards the better hearing musicians, as musicians with hearing complaints may have been reluctant of having their hearing tested. When retraction pockets fail to be self-cleansing they fill with debris and desquamated skin that can lead to secondary infection and bone erosion better known as cholesteatoma. If these examinations disclose evidence of hearing loss, referral for full audiologic evaluation is recommended.
Noise can cause permanent hearing loss at chronic exposures equal to an average SPL of 85 dB(A) or higher for an eight-hour period.7 Based on the logarithmic scale, a 3-dB increase in SPL represents a doubling of the sound intensity. There have been several attempts to identify audiometric notches according to objective criteria (Coles et al. In a GLM repeated measures analysis with gender as between subjects factor, and frequency band as the repeated measure, females show overall higher TEOAE-responses than males (average response over all frequencies 8.4 vs. Most musicians judged their hearing as good, though slightly worse than before (5 or 10 years ago). Consistent exposure to noise above 85 dB(A) causes an excess risk of hearing impairment [4] and every 3 dB increase in intensity halves the allowable exposure time. An audiogram hearing threshold level above 20 dB is considered abnormal.If the loss appears to be sensorineural, etiologies other than noise should be excluded. Qualitative descriptions most often showed a high pitched tone-like sound, but numerous variations were mentioned (e.g. As far as we could check, the self reports on medical history did not show deviations from the general population.When categorizing the musiciansa€™ pure-tone audiograms in absolute terms, almost half of the tested musiciansa€™ ears can be categorized as normal. NIHL is 100% preventable and the most effective ways to avert NIHL are by avoiding or reducing hazardous noise.Although, NIHL is well recognized as an occupational hazard, less recognized perhaps, are non-occupational leisure activities or environments that can put people of all ages at risk for hazardous noise exposure. The physical examination of the ears should assess presence of cerumen impaction or evidence of middle ear disease. While this type of loss in early childhood is often caused by congenital factors,22A  presbycusis becomes the most common sensorineural condition after midlife.
Although complete recovery from a given episode can occur, repeated episodes of such shifts occurring after noise exposures give way to permanent threshold shifts because hair cells in the cochlea are progressively lost.CASE 2A 55-year-old factory worker consulted his family physician because of ringing in his ears and depression that began soon after the onset of the tinnitus. The Weber and Rinne tests, performed with a 512-Hz or 1,024-Hz tuning fork can provide clues to whether the loss is conductive or sensorineural.
An extensive review of literature and data of the Vancouver Symphony orchestra concluded that at least some noise-induced hearing impairment among musicians can be shown from the PTA (Eaton and Gillis 2002).
No participants scored higher than a?’1.4, indicating poor hearing as defined by Smits et al. He had seldom worn hearing protection at work, where he had to shout to communicate with co-workers. In the Weber test (Figure 4), sound will lateralize to the side away from a sensorineural loss and toward a conductive deficit. Yet other studies report musiciansa€™ hearing threshold levels that do not significantly differ from those of non-exposed populations (e.g. In these studies, audiograms are usually divided in normal hearing, age related hearing loss, and noise induced hearing loss. The DR covers 45 critical units and provides information about the range in which a person can hear properly.
This could suggest an effect of exposure as low-string players are usually the least exposed group (Boasson 2002). Away from work, he had difficulty understanding conversations in crowded rooms, and he said he often argued with his wife about the volume of the television set. The Rinne test (Figure 5) will demonstrate air conduction better than bone conduction if the loss is sensorineural.
Applying these criteria, most of the audiograms of our musicians would be identified as normal hearing, a few as NIHL and some as age related hearing loss. This is strongly related to the phenomenon of recruitment that usually accompanies hearing loss from a cochlear origin.
The clinician can motivate patients to maintain their hearing health and thereby reduce the risk of hearing disability as they grow older (Tables 2 and 3).
Again, females show stronger intensity levels than males, especially in the higher frequency regions (average response over all frequencies 8.0 vs.
Key factors in this effort are learning to avoid excessive noise when possible and correctly using hearing protection when necessary. On the other hand, the assessment of musiciansa€™ hearing by means of the PTA could lead to very different results than that of, for instance, workers in the building industry. For safety purposes, the maximum output was limited to 105 dB (SPL), according to the JBL control1X specifications. When asked to further clarify their answer, 12 (5%) thought they would not be a good musician in case of hearing problems, 6 (2%) stated that they thought their colleagues would doubt their ability to function as a musician. The patient was referred to an audiologist, who confirmed a sensorineural hearing loss that was probably caused by excessive noise exposure, with superimposed age-related changes. Hearing protectors, including earmuffs, disposable earplugs and custom-fitted earplugs, can provide 20 to 40 dB of attenuation when used correctly.
With their well-trained ears and developed sensitivity to sound and music in general (Seither-Preisler et al.
Based on the participanta€™s judgment of the loudness of the test sound for various intensities, an individual loudness curve was fitted. Therefore, we used a rather strict criterion for a€?normal hearinga€?, and more specific criteria for the degree of the noise notch.
This made some participants reluctant to talk about it or to take measurements associated with hearing problems (i.e.
This supports the observation that professional musicians perform relatively good on pure-tone audiometry despite intense exposure. Physicians can obtain samples from manufacturers and keep them in the office for distribution and demonstration of techniques for proper use. 2007), musicians could simply be better in detecting pure tones than other populations.The measurement of otoacoustic emissions (OAEs) has been proposed to be a more objective and more sensitive test for assessing the effects of noise exposure than the PTA.
It is possible that this effect is able to mask early signs of NIHL and in that case screening techniques other than the pure-tone hearing thresholds could be more adequate for the detection of early stages of NIHL in professional musicians (e.g. OAEs are sounds produced by the healthy ear, by the outer hair cells (OHCs) in the cochlea.
First, participants had to match the loudness of the tone in the left ear to the tone in the right ear, presented at 60 dB HL. The focus of this research endeavor on headphone use with MP3 players (instead of lowering the volume) was used for the following reasons. The absence of OAEs is associated with poorly functioning outer hair cells resulting in reduced selectivity and a decreased sensitivity (e.g. Then, the musician was asked to match the pitch of the tone in the left ear to that of the right ear.
Despite this fact, our material showed that the thresholds at 6 kHz were nevertheless poorer than in the ISO 7029 (2000) population. First, students entering college in the USA are very likely to have been exposed to NIHL prevention messages that focus on reducing volume. This finding suggests that at least some hearing loss in musicians can be associated with the duration and intensity of the music that they are exposed to. In other words, by switching to headphones a student could listen to music for twice as long as when using earbuds. Tinnitus is a common symptom of noise overexposure, and it further interferes with hearing acuity, sleep and concentration.
In case of clear lateralization, the matching sound was presented to the contralateral ear.
Accordingly, an attempt was made to assess the hearing status of professional musicians more profoundly, not only by specific hearing tests but also by the use of self reports.Hyperacusis, an increased sensitivity to sound at levels that would normally not be of discomfort to an individual has been associated with exposure to sound and is often reported in people with a known hearing loss (Katzenell and Segal 2001). Finally, by selecting a message that teens are unlikely to have been exposed to while in primary school, the effect of a specific communication model or theory on health risk knowledge and intentions could be more accurately measured in this study.Using an approach based in communication theory to achieve the goal of effectively informing young people of the threat they face for NIHL and then outlining effective ways to avert that threat seems particularly useful. When it was localized in the middle, the matching sound was presented to the audiometrically better ear. This study used the EPPM [19] to design and evaluate the creation of brochures targeting college students that highlight threats associated with exposure to extreme noise and the efficacy with which hearing protection can be used. She found no significant correlations between changes in audiometric thresholds and changes in OAEs, which is suggestive for the hypothesis that OAEs indicate noise-induced changes in the inner ear, still undetected by pure-tone audiometry. The current study represents the first step towards the goal of reducing risk of NIHL in undergraduate college students (typically 18 to 21 years of age) and simultaneously tests the ability of the EPPM to guide effective message development in this population.
When confirmed by further experimental evidence, the measurement of OAEs could be an attractive method to assess NIHL in musicians in an early stage.Diagnosis of NIHL has often been limited to the measurement of hearing thresholds, while musicians specifically report other sound related hearing problems.
In this study, a large number of musicians indicated to have severe complaints about hyperacusis, but the average UCL values were only slightly lower than that of non-exposed populations.
This goal is particularly important given that frequent or prolonged exposure to hazardous noise levels leads to permanent NIHL (and often constant tinnitus) the consequence of which can include decreased enjoyment and quality of life, depression, lower academic performance, and reduced productivity. We have to be cautious on this matter as data from other studies are not directly comparable. The SRT test uses an adaptive procedure, a simple one-up one-down procedure with a step size of 2 dB.
Keller (2006) found higher average UCL values, but she used different stimuli, and a different procedure to determine these values. Specifically, the impact of NIHL on communication includes: Difficulty hearing speech from a distance, in noisy and reverberant environments, and when it is softly spoken.
Participants responded to each set of three spoken digits (triplets) using the laptop digit-keys. Our UCLs were based on noises retrieved from binaural conditions, while Keller used pure tones measured monaurally.
This is in disagreement with the results from Kellera€™s study, but corresponds to earlier findings of Morgan et al. To the extent that this combined presentation of threat and action instigates protective motivation, recipients reduce the threat in the way advocated by the appeal.
Each test day the probe was calibrated before OAE-measurement.TEOAEa€™s were evoked using a 80 dBpeSPL click stimulus.
The fact that the dynamic ranges decreased with increasing pure-tone thresholds might indicate some association with NIHL.
According to the EPPM, perceptions of threat require that the young person receiving the message believe that the health hazard is severe and that they are susceptible to injury or harm. When applying the EPPM to leisure NIHL, the college student, for example, must perceive that hearing loss is a real threat to their well-being and that they are susceptible to hearing loss. If a threat is considered to be trivial or irrelevant, the model predicts that the student will not be motivated to process and accept the message and no action will be taken to prevent injury. The criterion for the definition of diplacusis used here, an interaural difference of more than 1%, could have been too strict. It is difficult to find evidence on this matter, but in at least one study (Markides 1981) interaural differences of more than 2% are still considered to be normal. Diplacusis did not seem to cause real problems for musicians, as just a few indicated to struggle with it. According to the EPPM, efficacy is composed of two elements: Perceived self-efficacy and response efficacy. On the other hand, musicians with diplacusis had increased average threshold levels while the average age for the groups did not differ, indicating that diplacusis is related to other forms of hearing impairment, possibly NIHL.12% of men between 65 and 74 of age experience some kind of tinnitus and its prevalence increases with age (Lockwood et al.
Response efficacy refers to the perception that the recommended action to avert the threat (or injury) really will protect a college student from harm.
Response efficacy refers to the perception that HPDs will adequately protect against future hearing loss due to hazardous leisure noise exposure and will protect against the negative personal and financial consequences that hearing loss can bring.According to the EPPM, an effective prevention message is created with a balance between threat and efficacy. The danger-control process is desired because it motivates a young person to employ protection behaviors, which will prevent the negative outcomes associated with health hazard. In the fear-control process, college students engage in denial, defensive avoidance, reactance, and ultimately reject the message in order to escape their fear Witte.
The tinnitus reported in this study usually had a temporary character, but some participants reported very loud and continuous tinnitus.
No more than 40 subjects were grouped at any one event, and subjects were only allowed to participate in the study once. This sample was reduced to 176 after removing subjects with a self-reported history of hearing loss.
Tinnitus was more often localized utmost left and this could not be related to the instrument type (e.g. In the control condition, subjects responded to a questionnaire designed to measure the EPPM variables of severity, susceptibility, response efficacy, self-efficacy, and behavioral intentions, as well as several demographic variables.
As with diplacusis, musicians with tinnitus showed increased hearing thresholds, while no difference in age could be found with musicians who did not report tinnitus.Most musicians scored within normal limits on the speech-in-noise test.
After completing the questionnaire, these subjects received the brochure so as not to withhold any benefits of the brochure from the control condition. PTA, OAE) and self-reports on noise-induced hearing problems.In both TEOAEs and DPOAEs large inter-individual differences were found. After being given a few minutes to review the brochure, subjects responded to the same questionnaire that was administered to subjects in the control condition. In both conditions, subjects were instructed to ask the researcher if they had questions or needed clarification while completing the measure.
On group level however, we found clear differences between the average OAE responses of different audiometric subgroups: in general, more intense OAEs were found for groups with better average pure-tone thresholds. None of the subjects needed any clarification.Brochure and measurementBrochurebrochure was designed specifically for a target population of college students focussing on two different types of behavior. The OAEs of the normal hearing musicians were clearly distinguishable from the OAEs of the musicians in the other audiometric categories, suggesting a signalling function for early detection of NIHL. Specifically, the two qualitatively different activities of portable audio device use and student leisure activity engagement were considered. A firm statement on this issue can, however, only be made on the basis of a longitudinal study. The dissociation between audiometric thresholds and OAE outcome measures can be a complication in the application of OAEs for screening purposes on an individual level. Consequently, people's motivations to engage in behaviors to protect hearing may be very different across the two behaviors resulting in the possibility of observing a differential pattern of results. Thus, each page of the brochure contained messages developed to make salient the threat college students face for NIHL and increase the perceived efficacy of behaviors that can avert the threat. The messages contained in the brochure were collaboratively designed by an EPPM expert and an audiologist with NIHL expertise.
The NIHL data contained in the brochure was provided by an audiologist with expertise in the area. The EPPM variables were measured using five-point Likert-type scales ranging from "disagree strongly" to "agree strongly" where higher scores corresponded to greater item endorsement.
Threat was also hypothesized to be second-order unidimensional and composed of the constructs of susceptibility (SUS) and severity (SEV).
Only responses to the RE and SE items for wearing formable earplugs in loud environments were considered for these analyses. Analyses of responses to the RE and SE items for wearing over-the-ear headphones when listening to MP3 players were conducted separately.After examining the response distributions of each item for normality, the 20 item inter-item correlation matrix was examined for items lacking internal consistency and parallelism.
The results of these analyses yielded four potentially content valid indicators of RE, four of SE, four of SEV, and five of SUS. The AMOS 16.0 Confirmatory Factor Analysis (CFA) algorithm using a maximum likelihood parameter estimation method was employed to test the hypothesized measurement model. Examination of the obtained parameter estimates presented in [Figure 3] reveal that they are all ample. Furthermore, examination of the modification indices suggested there were no localized areas of substantial model misfit.
An efficacy index was created by averaging (arithmetic mean) across responses to the four RE items and four SE items, whereas a threat index was created by averaging across the five SUS items and four SEV items.
As was the case in the loud environment analysis, efficacy was hypothesized to be a second-order unidimensional construct composed of the constructs of RE and SE and threat was hypothesized to be second-order unidimensional and composed of the constructs of SUS and SEV for the MP3 player analysis. RE, SE, SUS, and SEV were each measured by a set of five items.Using the same procedures of initial analysis as applied to the loud environment data, the same four potentially content valid indicators of RE, SE, and SEV and five potentially content valid indicators of SUS emerged in the MP3 data. CFA also using the same procedures as applied earlier was performed to test the hypothesized measurement model with the MP3 data. The obtained parameter estimates presented in [Figure 4] are all ample, and the modification indices suggested there were no localized areas of substantial model misfit. The efficacy index was created by averaging across responses to the four RE items and four SE items, whereas a threat index was created by averaging across the five SUS items and four SEV items. HypothesesLoud environmentseffects of the EPPM brochure on threat, efficacy, and intent to wear ear plugs in loud environments are presented in [Table 1]. Hypothesis one predicted that college students who received severity and susceptibility of hearing loss messages would rate the threat of hearing loss higher than students who did not receive the messages. These results indicate that the loud environment data were indeed consistent with hypothesis one.Hypothesis two predicted that college students who received messages with response efficacy and self-efficacy components would rate efficacy of using ear plugs in loud environments higher than those who did not receive the messages. Intent was measured by a single item focusing on the intent to use ear plugs when in loud environments in the future. Hypothesis 1 predicted that college students who received severity and susceptibility of hearing loss messages would rate the threat of hearing loss more highly than those who did not receive the messages.
The results of a multiple regression analysis indicated that the MP3 player data were consistent with hypothesis one.
These analyses were consistent with hypothesis 2.Finally, hypothesis three predicted that students receiving messages with threat and efficacy components would have greater intent to use over-the-ear headphones than would those who did not receive the messages.
One item, focusing on intentions to use over-the-ear headphones while listening to MP3 players in the future, was used to measure intent.
Exposure to the brochure created perceptions of increased threat of NIHL resulting from loud environments as well as MP3 players. Brochure exposure also resulted in increased perceptions of the efficacy of using ear plugs as well as the efficacy of using over-the-ear headphones to avert the threat of NIHL.
Exposure to the brochure only increased behavioral intentions to use over-the-ear headphones, however, and not behavioral intentions to use ear plugs. Put differently, the brochure produced statistically significant changes in only the threat and efficacy variables for the loud environment data whereas the changes produced in all three variables for the MP3 data were ample and statistically significant.Although it could be argued that the lack of effect on behavioral intentions to use ear plugs when in loud environments is due to a failure of the EPPM, an alternative argument could be made. It is possible that wearing ear plugs is a response that no matter how effective the intervention used, will not be changed easily, if at all.
In other words, the impact of threat and efficacy on intentions when the baseline is below the threshold is smaller than the impact of threat and efficacy on intentions when the baseline is above the threshold. Such threshold effects, or more precisely effect nonlinearity, result from the presence of a moderator variable. Similar effects have been observed in research focused on encouraging college students to wear bicycle helmets while riding their bikes on campus. As a result, although the brochure brought about increases in the perceptions of threat and created a substantial increase in the efficacy of the recommended response, an unobserved moderator variable may have attenuated the effect on intentions causing people to engage in fear-control processes that resulted in people failing to engage in the response recommended to avert the threat. As a result of the higher level of one of these moderator variables the effect on intentions was not attenuated and people engaged in danger-control processes and intentions to wear over-the-ear headphones when using MP3 players in the future were increased.
Based on the findings of this study, the likely moderator variable is related generally to the desirability of performing the recommended response.
This study did not include such a measure and it resulted in the need to make inferences of desirability based on the efficacy, threat, and intention perceptions that were measured. For example, although perceived as efficacious, the recommended response of wearing ear plugs in loud environments could have been seen as undesirable, perhaps because it would be perceived to get in the way of hearing sounds in the environment that need to be heard.
Having a way to measure issues of response desirability would allow the researcher to diagnose its status as a moderator variable, determine how much impact it had on EPPM processes, and in turn control for or reduce that impact.Future examinations of the EPPM would also be well served at improving the quality of instrumentation used to measure the EPPM components.
The measures employed in this study were improved versions of the the risk diagnosis behavior scale.
The measures in this study also included additional items to measure each of the variables. Although, fewer items on a questionnaire can be advantageous pragmatically, too few a items can result in problems assessing the measure's validity and reliability. Therefore, paying a small price in practicality allows for the disposal of items displaying misfit during testing of the measurement model, but also an increase in reliability estimates as long as the items are of equal quality to the existing items. Therefore, it is recommended that the response scales for each item be increased from five-point to seven-point response scales, which will serve to relieve the equivalent of a restriction in range problem attenuating the reliability coefficient. When the message development phase of a communication effort begins, at a minimum, the messages will have to include threat and efficacy components. Moreover, the threat component must convince the intended message recipients of their susceptibility to the condition by making arguments that the condition can and does happen to people just like them.
In addition, the threat component must include messages that convey the severity of the condition. In other words, the message must convince recipients that they are at risk of grave potential harm. Leaving the message recipients without an efficacious means to deal with the threat, however, may lead to counterproductive responses intended to control fear. Therefore, for these situations brochures can be helpful to inform of the threat and efficacy of a response but will not be sufficient to improve intentions to engage in the response. In these cases, practitioners will need to search for alternative responses that have similar levels of efficacy but higher levels of baseline intent. For situations where only one recommended response is possible, further research must uncover the potential moderators that may be attenuating the EPPM's effect on intentions and design messages aimed at reducing their impact on the target's intentions to engage in the recommended response.



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Comments Noise induced hearing loss test program

  1. Boz_Qurd
    Possibly also result in temporary or permanent.
  2. EMRE
    With tinnitus ear ringing you would displayed in the sample.