Subscribe to RSS

New Yorkers are willfully resigned to a life of noise, particularly while riding through the city's 109-year-old subway system. But the heavy machinery and train cars that create a daily metal-on-metal cacophony can be harmful to your ears. On a recent Monday afternoon, a week before the start of National Protect Your Hearing Month, amNewYork joined Herget at several Manhattan stations to find out exactly how loud the subway system can get. Using a sound-measuring device, trains barreling into transit hubs like Times Square and smaller local stations ranged from 92 decibels to 102 decibels, a level people can be exposed to for up to 15 minutes without damaging hearing.
The measurements were consistent with a comprehensive 2009 study into transit noise in the American Journal of Public Health. The MTA has been trying to quiet its noisy subway system since the mid-1970s, including lubricating tracks on sharp curves, using quieter train wheels, and installing composite brake shoes on all subway cars to stop wheels from screeching, according to agency spokesman Kevin Ortiz. For MTA workers, the agency requires an annual hearing test and hearing protection for employees exposed to at least 85 decibels over an eight-hour shift.
Tom Carrano, the director of subway safety at the Transport Workers Union Local 100, said that the union pushes for ways to quiet the workplace by using newer machines or relocating a noisy piece of equipment away from workers.
But riders said the noise is just a fact of life in New York City, even if it can be annoying.
Afiya Benn, a 26-year-old secretary from Canarsie, said she is used to the sound, though admitted to cranking up the volume on her music device when a station get too loud.
The original Aikido All-in-One design combined a 9-pin Aikido line stage amplifier and high-voltage B+ power supply and a regulated low-voltage heater power supply on one PCB, thereby greatly reducing the stress level of many Aikido fanciers. I used 6CG7s as the input tubes and 6DJ8s as output tubes, with the output stage configured as a White cathode follower.
I know this from recent experience, as I have just built up a 12SX7-based Aikido headphone amplifier and, although it offers ear-pleasing midrange sweetness, its relatively high output impedance imparts a bloated bass to the HD-650s that I cannot abide.
I have no real reason for pasting the above image of the new Sennheiser HD-800 headphones, other than I would dearly love to listen to them with my one of my tube-based headphone amplifiers. So how does this new All-in-One Aikido sound as a headphone amplifier, albeit only paired with HD-650s? Conversely, if we want to play back organ music at low volume settings, we must boost the bass to compensate for the perceived lack of bass.
But even when we use the latest set of equal-loudness-level curves, we realize that the old loudness control was incomplete, as it only worked in one direction: more bass with lower volume. We need a loudness control that is independent from the volume control and that offers a flat position in the middle of its rotation and then a boost or cut in bass (and, to lesser degree, high frequencies). Well, for me, the best feature this tube headphone amplifier offers is that I can happily listen at lower volume levels, which is important, as I often listen for hours and I do not want to damage or even weary my ears. Loud sounds that do not produce discomfort, let alone pain, can nonetheless cause damage to ear, if the sound persists long enough.
By the way, I have a theory that many are listening to headphones at far too loud a volume setting these days because many are listening to MP3 files. I have created small, 4 by 6 inch PCB that holds a low-voltage bipolar regulated power supply for solid-state use. Remember electrons only flow from negative to positive, so even a negative regulator, such as the LM337, is not going to make the electrons flow backwards. This regulator requires a power transformer with two secondaries, as it uses two four-diode rectifier bridges. The B-PS-1 regulator costs $69, which includes all the parts to populate the PCB, but not the power transformer. Last time, I mentioned that what troubled me about Blumlein’s garter circuit was that it effectively threw away half of the error signal by using two large-valued cathode resistors in series per output tube, thereby creating 50% voltage dividers, so half of the error signal was thrown away, which prompted me to think of a workaround.
The two-battery variation should have worked better was my firm conviction, so I reviewed the results and I saw that two variables had changed, the addition of the batteries and the halving of the cathode resistor value. Now, the results match my expectations, as the circuit with the batteries does provide a tighter current matching. The Chinese-cathode-cuff circuit can be used with (or without) the Blumlein or my variations on the garter circuits or with just a single cathode resistor in an SE amplifier. See why this circuit is the equivalent of the Chinese thumb cuffs, with the toy, you pull your thumbs very slowly and they come free; pull quickly, you are caught.
Expect more soon, such as an octal All-in-One Aikido PCB, with the same power supply as the original Aikido All-in-One.
I bought an Aikido stereo linestage kit from you some days ago, and I received it just this Monday. High-quality, double-sided, extra thick, 2-oz traces, plated-through holes, dual sets of resistor pads and pads for two coupling capacitors.
The Tube CAD Journal's first companion program, TCJ Filter Design lets you design a filter or crossover (passive, OpAmp or tube) without having to check out thick textbooks from the library and without having to breakout the scientific calculator.
While the program’s main concern is active filters, solid-state and tube, it also does passive filters. Tube crossovers are a major part of this program; both buffered and un-buffered tube based filters along with mono-polar and bipolar power supply topologies are covered.

When checked, Shutterstock's safe search screens restricted content and excludes it from your search results. Chris Herget, an audiologist who practices at New York City Hearing and Balance in midtown. And even though trains can enter and leave stations quickly, repeatedly listening to that level of sound from a platform can contribute to hearing issues, like tinnitus, the ringing in one's ear, over time, Herget said. In addition, I set a purposely low B+ voltage of only 140Vdc, as I wanted to run a heavy current through the output tubes, without exceeded their dissipation limits or excessively shorting their lives.
Of course, some would love the sound from this 12SX7 headphone amplifier, finding it just right.
If this new model offers as substantial an upgrade from the HD-650 as is rumored, then a fantastic headphone and tube headphone amplifier setup could be readily put together. For most audiophiles, the louder the better, just as a film buff might clamor for the biggest movie screen possible.
Such a loudness control would be more of a help for the average audiophile, as most audiophiles love cranking up the volume, often requiring a bass cut; whereas most music lovers are content to listen at low volume from kitchen radios, usually requiring a bass boost. My brother owned a pair of high-quality Shure microphones and I preformed a few interesting experiments. The following table is from an excellent article, Preventing Hearing Damage When Listening With Headphones, from the HeadWise website. What if the loss-full compression used to decrease the audio file size also compels a louder playback volume in an attempt to regain some of the thrown away detail? And the new All-in-One LSA\HPA will not disappoint them, as a first-rate line stage amplifier can be assembled just as easily with the new board.
The two 6CG7s offer a sweet, high resolution amplification and unity-gain output stage buffering. The heatsinks are 2.5 inches tall and provide plenty of cooling for the two LD1085 regulators. The workaround with two batteries didn’t seem to pan out, which bothered me a great deal, so I went back to SPICE simulations.
The following circuit shows a garter circuit variation that uses two 50V batteries with 1k, not 500-ohm, cathode resistors (the B+ was increased to compensate for the increased cathode resistor(s) voltage drop). They were small woven tubes that allowed both thumbs to be inserted readily, but clamped down, when the fingers tried to escape the cuff. In the circuit, subsonic shifts in the cathode voltage are allowed, but audible changes in cathode voltage are not. I even notice this when trying to read resistor color bands I dim light; in the dark, all resistors are 100k. This program's goal is to provide a quick and easy display not only of the frequency response, but also of the resistor and capacitor values for a passive and active filters and crossovers. In fact, it can be used to calculate passive crossovers for use with speakers by entering 8 ohms as the terminating resistance. So, for example, in the photo above, you can see seemingly missing parts, but those parts were not needed for the headphone amplifier configuration. Note how it no longer terminates solely into the output tube, but now encompasses the input tube as well.
I have no problem with that, as what could be the goal of high-end audio other than individual pleasure. And having watched movies on my Zune’s 3 inch screen, I can go along with a desire for a bigger picture screen, but hearing is not seeing. Yes, yes, I know that most loudness controls sounded terrible, being no more than just super bass boosters.
In other words, a truly useful loudness control must work in both ways, contouring the frequency to music (or sounds in general) played too softly or too loudly.
I ran long leads of cable out of the listening room to the living room, then to the backyard, where the two microphones sat in stands waiting for some sound to capture.
It seems to me that this would be a perfect PhD dissertation topic and an easy way to fifteen minutes of fame, if the results of a few simple experiments proved my hypothesis correct; let test subject set the playback volume for the same songs but with different levels of signal loss in the audio file format. I have yet to create a user guide for it (it's going to be thick), but it should be fairly easy, as I can stitch together the two old user guides into one fat guide. Resistor R12 is replaced with a jumper wire and smaller-valued coupling capacitors are used, along with a higher B+ voltage. I have been experimenting with OpAmp circuits lately and I needed a killer low-voltage, bipolar power supply. For example, imagine walking into an electronic store and asking for a negative 9V battery and being given an off-the-shelf 9V battery.
At idle, just imagine the NPN transistors are not there, as their bases are insufficiently positive to turn the transistors on. One advantage that PNP transistor would hold over its NPN brother in this circuit is that the tab is connected to the collector, which with the PNP transistor will be tied to ground, so less of a shock hazard exists (they might even be attached directly to the chassis, although I doubt that a heatsink would ever be needed). I know you do this because you love audio, but I think your price of $39 is a bit of a giveaway!

In other words, I built up a headphone amplifier on this board, which helps to explain the large coupling capacitors and the dissimilar input and output tubes. I have in the past built tube headphone amplifiers that dripped with sweetness, but lacked detail; and solid-state headphone amplifiers that delivered piercing detail, but frayed the nerves. For example, too big a movie screen will never cause your eyes to hurt, whereas too loud sounds will make your ears bleed. Yet a spectrum graph of the quiet whisper and its amplified reproduction would display the exact same frequency distribution. Nonetheless, the motivation behind adding a loudness control is defensible, as music played back at low volume levels sounds weak and thin. They are tied to the volume control, so they cannot be adjusted independently from the volume control. For example, an a cappella singer played back at 100dB will not sound right, even if the loudspeaker and electronics are blameless. In front of the microphones my brother and friends played acoustic guitar, sang, jiggled car keys, and spoke, while I was in the house listening to loudspeakers reproduce live sonic events. Then, the media would go into hysterical old lady mode and the American government would outlaw low-resolution audio files and trail lawyers would be lining up at Mercedes dealerships, their pockets filled with cash from Apple, Sony, Microsoft, and the Moving Picture Experts Group founding members.
You complain, telling the salesman that the battery is clearly a positive 9V battery and that you need a -9V battery. The 30µF, 250V, polypropylene coupling capacitors are made by Dayton and were intended for loudspeaker crossover networks. After some experimenting, I found that this rearrangement further reduces distortion, always a worthwhile goal. One thing I immediately found impressive was the absence of the urge to turn up the sound level. In addition, the ear can only tollerate a small amount of distortion, whereas the eye feels no pain at seeing near infinte visual distortion.
Thus, if we want to hear a tonally-natural amplified whisper, we must cut some of its bass first. The old-timer barely contains his chuckle as he tells you that you are holding the battery wrong, that if you hold it the other way around, it becomes a negative 9V battery. Their job is to limit the charge-building rectification effects during loud, sustained passages. A long-time TCJer wrote to me, telling me that these were the killer coupling capacitor for headphone amplifiers.
In fact, for each recording, I was instantly able to set the volume control to the right value.
The first roadblock I encountered was that the famous Fletcher–Munson curves are certainly famous, but not so accurate. The sound was so immediate and genuine sounding that all recordings, whether on LP or tape, sounded absolutely compressed and canned by comparison.
I should mention that I had only 11 boards made (I am keeping one for myself), so they will not last long. In Fact, I may not bother, as I have heard the PS-1 and stereo 9-pin Aikido pairings many times before.
But under idle or low-signal conditions, the added transistors just drop out of the circuit and do nothing. Much of the impact that music can deliver is missing from headphone listening because our body misses the somatosensorial wallop that big drums dispense.
It was then that I realized that the recordings themselves were the weakest links in the audio chain. When the cathodes quickly starts charging up, however, the transistors turn on and apply the brakes to the cathode's climbing voltage.
I had been using large, 47µF, 630V Solen coupling capacitors in my headphone amplifiers and while the Dayton capacitors definitely sounded better, they were not hugely better. My primary headphones are the Sennheiser HD-650, which can sound bass-flabby with too high an output impedance.
In addition, I found that I knew exactly what the right volume setting was; too much was definitely too much, just as too little was obviously too little. On the other hand, if long sustained high-wattage output is needed (organ music perhaps), the added transistors just drop out of the circuit once again, as the 100µF capacitors will slowly charge up and turn off the transistors.
Why wasn’t this true with records, I asked myself, as the playback volume level could pretty much be arbitrarily, without the ear complaining, or, rather, all volume settings sounded equally off base. Without the this additional circuitry, all self biased power amplifiers face the problem of excessive cathode-bias voltage build up, as the amp moves beyond its class-A operating window. The added diodes are there to provide a discharge path for the additional 100µF caps, when the loud passage ends.

How to stop your ears from ringing after the club letra
Signs of hearing loss in baby names
Hearing loss support groups uk quito

Comments to «Ear pain from loud noises»

  1. Fitness_Modell writes:
    Ear and ear pain offered the medical doctor can execute.
  2. Avara writes:
    Except in very loud noise, if you have between tinnitus and.
  3. KISSKA325 writes:
    Nausea and vomiting, hearing loss.
  4. tana writes:
    Come as no surprise to many that a new study.