[Awk.Pine]

The OSHA standards list a noise level and time period at which there will be permanent hearing loss. Don't discount these warnings because you've experienced louder noise for longer; these standards are to protect against exposure over a working lifetime. You can be exposed to high noise and experience nothing, or just a temporary threshold shift. You may not notice the damage being done week to week, or even year to year, but over 40 years there will be hearing loss. And, frankly, I expect to have more disposable income for things like headphones 40 years from now, and I want to be able to enjoy them at that time, too.

For the study that founded OSHA's standards, see Criteria for a Recommended Standard: Occupational Exposure to Noise.

For what it's worth, I understand that the EU has even stricter standards. All the OSHA standards try to protect is the intelligibility of speech, not the full function of the ears.

...as far as IEMs go, I recently picked up a pair to block out noise, and I find myself more sensitive to environmental noise now. I think they're helping my ears, not hurting them. But then, I'm listening at a very low level.

 

[MASTERTECH]

Quote:

Originally Posted by mrdeadfolx /img/forum/go_quote.gif If this is true I'm in deep ****

hearing loss is like hair loss you dont suffer from either?

 

[Zodduska]

Thanks for the link to that study, after reading some of it i feel I have a better understanding.

Quote:

Originally Posted by werdwerdus /img/forum/go_quote.gif bass frequency is far less damaging than midrange/treble at the same SPL.

Quote:

Beginning with Kryter in 1950, concern shifted from measurement of noise based solely on overall sound pressure to measurements which are more indicative of the response of the hearing mechanism. Consistent with this thinking, several modern damage risk criteria have emphasized limit setting by frequency bands, usually one octave in width. Two lines of evidence were responsible for this shift in thought. First of all, data on minimum audible field sensitivity and measurements of equal loudness indicated that the ear was not equally sensitive at all frequencies. It was found that the ear is most sensitive to acoustic stimuli in the frequency range of 2000 - 4000 Hz, and less sensitive to frequencies both below and above this range.

Quote:

Variables that are germane to interrupted exposures but do not play a significant role in limiting hazard from short-term continuous exposures further complicate the problem of how the ear responds and integrates noise over time. One such variable is the "acoustic" or "middle ear" reflex. When the ear is exposed to loud noise, the middle ear muscles contract, thus altering the impedance of the middle ear. This reflex, which serves to attenuate the noise reaching the inner ear, adapts out or disappears quickly if the noise is continuous and relatively unchanging over time. However, if the noise level varies considerably or is interrupted on a regular or irregular basis, then the reflex is sustained.

source:
VI. Development of the Standard
http://www.cdc.gov/niosh/pdfs/7311001d.pdf


I think this makes it harder to apply continuous industrial noise, or pink noise testing standards to that of music listening. It also explains why im not deaf. These studies are designed to protect loss in human speech intelligibility over a lifetime of uninterrupted high db industrial exposure in the workplace in a percentage of people exposed.

 

[electro house]

Quote:

First of all, data on minimum audible field sensitivity and measurements of equal loudness indicated that the ear was not equally sensitive at all frequencies. It was found that the ear is most sensitive to acoustic stimuli in the frequency range of 2000 - 4000 Hz, and less sensitive to frequencies both below and above this range.

http://www.cdc.gov/niosh/pdfs/7311001d.pdf

This is huge, if true.

Perhaps the bassheads will have the last laugh -- keeping their hearing longer than the more well-rounded audiophiles who often act as if the bassheads are a lower form of music listener.

 

[wolfen68]

Quote:

Originally Posted by electro house /img/forum/go_quote.gif Verbatim from my Superfi.5 manual, page 5: "Using earphones at high volumes (greater than 85 dB(A)) OR FOR EXTENDED PERIODS (MORE THAN 1 HOUR PER DAY) can permanently damage your ears." (emphasis added). It doesn't say "Dont listen to 85dBa+ for more than 1 hour." It says listening for more than 1 hour per day can damage your ears.

I'll explain why this statement exists (I'm an industrial hygienist by trade).

Whatever standard you look at, it is already well established that loud noise, especially for extended durations, is damaging to the ears. In the U.S., 85 dB is the workplace standard. It is also well known, and getting more recent publicity, that the ipod generation is overexposing their ears to damaging levels of sound. Therefore, legally speaking, how can a company such as UE cover themselves and guarantee that users are being exposed to less than 85 dB? Answer: They can't. They know their users will have no real control over determining what is the appropriate level to listen to (as that normally requires instrumentation that most people don't have). Therefore, to cap the recommended hours of daily usage legally gives them some shielding from any future potential lawsuits.

For the audiophile who wants to protect their hearing, the smart way to alleviate your concerns is to get your hands on a noise dosimeter and train yourself how to recognize sound levels that could cause hearing damage (85 dB is lower than you would think!). Learn to maintain a low safe level (low 70's has worked for me) and you can proceed with no worries (within reason).

Also, as you explore higher quality IEM's (or headphones in general) you'll find that you can find listening enjoyment at lower levels.

 

[dealmaster00]

Yeah, another +1 for the "they are trying to cover themselves" crowd. I have used IEMs for well over an hour a day many times and my hearing is fine

 

[werdwerdus]

Quote:

Originally Posted by Zodduska /img/forum/go_quote.gif ...

thanks for backing me up, I knew I heard it somewhere...

 

[naldo]

I had my er4's in for like 8 hours one day, hopefully theres no damage. Dont listen to them very loud though

 

[MASTERTECH]

Quote:

Originally Posted by naldo /img/forum/go_quote.gif I had my er4's in for like 8 hours one day, hopefully theres no damage. Dont listen to them very loud though

yeah IEMs in particular, lots of deaf people use them

 

[scompton]

Quote:

Originally Posted by wolfen68 /img/forum/go_quote.gif I'll explain why this statement exists (I'm an industrial hygienist by trade). Whatever standard you look at, it is already well established that loud noise, especially for extended durations, is damaging to the ears. In the U.S., 85 dB is the workplace standard. It is also well known, and getting more recent publicity, that the ipod generation is overexposing their ears to damaging levels of sound. Therefore, legally speaking, how can a company such as UE cover themselves and guarantee that users are being exposed to less than 85 dB? Answer: They can't. They know their users will have no real control over determining what is the appropriate level to listen to (as that normally requires instrumentation that most people don't have). Therefore, to cap the recommended hours of daily usage legally gives them some shielding from any future potential lawsuits. For the audiophile who wants to protect their hearing, the smart way to alleviate your concerns is to get your hands on a noise dosimeter and train yourself how to recognize sound levels that could cause hearing damage (85 dB is lower than you would think!). Learn to maintain a low safe level (low 70's has worked for me) and you can proceed with no worries (within reason). Also, as you explore higher quality IEM's (or headphones in general) you'll find that you can find listening enjoyment at lower levels.

Do you know of an accurate way to test sound levels for IEMs. I bought a SPL meter from Radio Shack because of a similar thread last month. I posted how I tested my UM1, but I have no way of knowing if it was accurate. http://www.head-fi.org/forums/showpo...&postcount=102

 

[platinum]

Quote:

Originally Posted by vYu223 /img/forum/go_quote.gif Whoa, really? I've had the complete opposite experience (at least so far, for two years). Please elaborate.

Well it's hard to tell.
2 years ago when I just started to listen to earphones,
my hearing ability is up to 14500 Hz, and today only 10000~11000.
provided that I am now only 18, these numbers are very bad results among this age.

 

[vulc4n]

Quote:

Originally Posted by platinum /img/forum/go_quote.gif Well it's hard to tell. 2 years ago when I just started to listen to earphones, my hearing ability is up to 14500 Hz, and today only 10000~11000. provided that I am now only 18, these numbers are very bad results among this age.

You seriously cannot hear above 11000Hz? You need to go to an audiologist dude.

 

[platinum]

Quote:

Originally Posted by vulc4n /img/forum/go_quote.gif You seriously cannot hear above 11000Hz? You need to go to an audiologist dude.

i have been found my ears have very unresponsive to high frequencies since I am 6 or 7.
In terms of normal conversation, i might need more time to think about what others are talking about since I cannot hear the complete spectrum that the voice covered.
in terms of music, i cannot hear high frequency so may result in low sense of space etc.

audiologist said i have nothing to do with

, but keep on checking the ability of my ears.



Jacky

 

[edstrelow]

IEM's and a few other circumaural phones which provide signifcant isolation, can even help your hearing by both reducing your exposure to ambient noise and allwing you to listen to music at lower levels, since you no longer need to overcome the ambient noise.
Of course, I realize that's not always how everyone listens.

 

[edstrelow]

Koss tried an interesting approach to the noise dose problem. Sound level monitors on the earcups.

The Red LED's flash when sound level gets up to about 95 dB, so you can check the levels before you put the phones on your ears.

The photo shows my refurbished set.

http://www.head-fi.org/forums/showthread.php?t=236902

These are still pretty nice phones, if you can get them running.