[alicecastillo]

It has been shown that hearing damage from headphones is more common than from loudspeakers because of close coupling of the transducers to the ears. Two types of hearing damage can result from exposure to loud noise: Sensorineural hearing loss and tinnitus. Diminished hearing can be corrected to a degree with hearing aids. Tinnitus is currently not curable, but there are treatments and devices to minimize its impact on the sufferer. You should contact your audiologist before its too late for the treatment of tinnitus. You can find more information on Tinnitus at http://www.metrohearing.com/tinnitus-treatment-causes.html
 

 

[obobskivich]

You're mis-representing what I said simply to have an argument. How quaint. When I said "think about it like radiation" it's along the lines of exposure - not anything to do with radiation itself. For example, when you have an X-ray, you're exposed to radiation. Quite a lot of it (relative to not having an X-ray), but you don't keel over. However if you have thousands of X-rays over a short period of time (like a month), that'll probably cause some problems. Same thing applies to loud noises - exposure to short bursts of relatively loud noises (I am not talking about big explosions) is probably not going to result in deafness. But exposure to lots of those bursts, or more continuous noises, over a period of time, will result in NIHL. There are guidelines that explain all of this. With instantaneous damage due to high intensity signals, you're usually talking about an explosion; that wonderful >140 dB range. There are some headphones that can actually push up on that (the Koss ESP/950 and Beyerdynamic DT48A.00 both come to mind), although I'm unsure how long they can sustain that output without damage (to themselves). That's where headphones get a bit scarier - you can sit there and plod along at 90 dB constantly and it will eventually have it's effects. 
 
Again, review the OSHA and CCOHS documents if you disagree (and if you're really that extremely well versed in both audiology and acoustics to decree that OSHA and CCOHS are wrong, I'd suggest emailing them and explaining how things should be changed - I'd also suggest contacting some sort of academic institution so that we can get the textbooks changed; sounds like this is important information). 
 
You made the argument that IEMs will save your hearing, because they attenuate at HF rather than LF. True, they do attenuate HF better than LF. But lets think about why: LF requires lots of damping to contain. HF does not. 
 
Anyways, the power behind the signal doesn't matter one lick - it's all about intensity. In other words, if I'm generating 10khz at 100 dB, that's dangerous. It doesn't matter if I need a picowatt or a megawatt to do it. It's too damn loud. And like I said, it's noise (intensity, whatever) that causes damage, not frequency. All frequency is going to tell us is what range of your hearing that you're going to lose (and the 18khz argument is simple - if you can't hear 18khz, it's already damaged). 
 
See:
http://en.wikipedia.org/wiki/Noise-induced_hearing_loss
 
 
Regarding the power argument - it's simple: show me how much power it requires to produce 10khz at 100 dB vs 10hz at 100 dB at say, 1 meter. The former is in the milliwatts, the later is in the tens of thousands of watts. You can use equally efficient transducers for both. The entire argument is based on speaker design/building as well as FOH experience. LF requires power. Lots of it. 
 
 
Quote:

 
 
Lower frequencies have more energy? I know this is a mechanical wave, I can't find the formula that relates frequency with energy, but would you mind explaining how is it possible that it works exactly the opposite of an electromagnetic wave (E = h * f)? Then again you were the one saying "think about it like radiation" I'd still like to see some proof of this. Then you go on to say what damages your hearing is noise, not frequency... you just said a lower frequency wave carries more energy (not right, but let's think so). More energy means more pressure, thus more damage, so frequency makes the damage be more or less effective. And because I can't hear a 18kHz it won't harm me? I guess I can go to Chernobyl and not die of cancer because I can't see the radiation. Kids, if you're reading this, do not play with high frequencies.
 
When I said hearing music helped prevent hearing loss it was kind of implied that it didn't mean blocking out noise with more noise. I mean if you're trying to save your ears, it wouldn't make much sense to crank up the volume. Thus the mention of using IEMs on the street even when not listening. I agree with the part about exposure, but I seriously think you have your concepts mixed up.

 

[proton007]

All arguments aside, there are a few points to take note:

1. long term exposure
2. sound pressure level > 85dB
3. noise (or conversely, isolation)
4. ear health in general (prevention from infections etc).

 
If you can prevent these, you can prevent hearing loss.
 
Contrary to popular beliefs, using earphones outdoors does not cause hearing problems *if* you have proper IEMs that provide high levels of attenuation. Chances are you'll keep the volume at levels lower than street noise.

 

[obobskivich]

^^^ This. 
 
Also, sort of related: InnerFidelity measures isolation for headphones and IEMs they test - it's worth looking at. As Etymotic explains with their monitors - broadband is usually not as common as we think, and just because you can't hear your kid brother yelling at you with your in-ears in, doesn't mean they're blocking everything equally. 
 
I'm not aware of anyone else that measures isolation. 

 

[LizardKing1]

There's no need to be sarcastic, if you can't present an argument convincingly, using passive-aggressive statements won't get you there.
 
I guess I formed my point wrong, it should have been something like this: HF has more sensitivity than LF in transducers, so the same power delivered into different frequencies will create sounds with different intensities. So HF doesn't do more damage than LF, but HF will more likely be the cause since it can increase intensity with much smaller power increases.
 
Headroom also measures isolation.
 
I'm not so sure about the frequency used determining where the hearing loss occurs. So if I get bombarbed by sine waves at 500Hz 120dB I'll loose hearing at 500Hz? That would mean people in clubs would have hearing loss at low frequencies, yet we observe it happens in higher frequencies. In the link you sent me it specifies the NIHL to happen around 4kHz, regardless of what frequencies contributed to the damage.

 

[obobskivich]

Your re-stated point is roughly what I've been saying all along; my gripe is with the argument that "brake squeal" and similar are somehow more damaging than other noises. Glad we could have this talk.
 
The secondary point - my understanding of NIHL is that yes indeed you would lose sensitivity in that range. It can be selective. The arguments I've heard for the "notch" are not that it is frequency invariant, but that it is a function of the "n-shape" frequency response found in most cheaper headphones - e.g. http://www.innerfidelity.com/images/AppleiPodEarBudssampleA.pdf 
The Wikipedia link is not all-encompassing and cites studies that found notches existing at a variety of frequencies (not just 4khz) - over-generalizing and over-simplifying topics does not allow for a meaningful discussion.
 
HF roll-off is, again, a function of age. As you get older you lose HF sensitivity. http://en.wikipedia.org/wiki/Presbycusis
 
LF attenuation is biologically latent, it's also hard to measure LF because we "hear" (sense) a lot of lower frequency energy through compression and conduction - part of the reason you need so much power for effective low-end output. My understanding is that it's basically impossible to truly destroy all LF sensitivity, without paralyzing the person, because a good portion of it is a result of conduction and compression. I have not read anything about quadriplegics and hearing, or about full-deafness and LF sensitivity, but my guess would be that the former group probably has a worse chance of "feeling" pressure waves than the later group. 
 
Extreme HF/LF sensitivity isn't a "big" concern with audiometrics, because it doesn't impact physical orientation or speech/language like mid-band attenuation will. If you shred up your hearing at 4khz it impacts your functioning in daily life; if you shred it up at 18khz it really doesn't matter. 
Quote:

There's no need to be sarcastic, if you can't present an argument convincingly, using passive-aggressive statements won't get you there.
 
I guess I formed my point wrong, it should have been something like this: HF has more sensitivity than LF in transducers, so the same power delivered into different frequencies will create sounds with different intensities. So HF doesn't do more damage than LF, but HF will more likely be the cause since it can increase intensity with much smaller power increases.
 
Headroom also measures isolation.
 
I'm not so sure about the frequency used determining where the hearing loss occurs. So if I get bombarbed by sine waves at 500Hz 120dB I'll loose hearing at 500Hz? That would mean people in clubs would have hearing loss at low frequencies, yet we observe it happens in higher frequencies. In the link you sent me it specifies the NIHL to happen around 4kHz, regardless of what frequencies contributed to the damage.

 

[DiscoProJoe]

I like listening to loud music for at least an hour or two on most days, so to "soften the blow" to my long-term hearing there are some things I practice:
 
1. I always vary the volume level and give my ears little "breaks" during these times
 
2. If I really want to play it super loud to get my thrills, it's only for a few seconds. Then I turn it back down to a much more "reasonable" loud level during that hour of fun.
 
3. I use headphones and equipment that have a very "full" type of sound with a wide frequency response that covers the full human range of hearing.  If I'm listening at a cumulative, overall level of 100dB, it makes sense to "spread it out all the way" among 10Hz to 20kHz, rather than have an overall level of 100dB that's all concentrated at one single pitch (or narrow range). I would think the latter would damage your hearing a lot worse than the former -- like comparing someone lying on a bed of one nail (ouch!), versus a bed of 100,000 nails (no problem).
 
4. I always wear earplugs at concerts, bars/nightclubs, and sporting events. If not, these would always make my ears hurt. These always have loud sounds that are concentrated in narrow frequency ranges, and to my unprotected ears, it feels like lying on a bed with a very small number of nails (ouch). The funny part about this is how strange people thought I was at the conclusion of the event...to exit the venue, pull out my earplugs, hop into my car, and crank up my huge sound system!  I didn't think it was strange at all, because the "full" sound of my stereo system never hurt my ears, since the overall sound level was balanced and spread out over my entire hearing range, like lying on a bed with tens of thousands of nails that doesn't hurt.
 
Finally,...
 
5. I make sure I get good nutrition, good exercise, and good sleep. This helps your body heal itself better, which includes your ears and helps with short-term hearing loss, especially.
 
That's my take on this, at least.