[stalepie]

Can someone point me to a scientific paper that provides studies showing this?

*causes

 

[Slaphead]

This might help.

https://www.osha.gov/SLTC/noisehearingconservation/

And yes it's been proven and well known that prolonged exposure to sound levels above 80dBA can and does cause hearing damage. The louder the noise the less time you can be exposed to it.

http://www.noisehelp.com/noise-dose.html

 

[stalepie]

Neither of those are links to studies. I figure it would be unethical to do, though perhaps done on prisoners in the Soviet Union or something at one time.

 

[obobskivich]

Neither of those are links to studies. I figure it would be unethical to do, though perhaps done on prisoners in the Soviet Union or something at one time.

The OSHA/CCOHS data draws on experience in industrial environments (you may want to educate yourself on the history of OSHA and CCOHS and what their function is) - they don't have to torture people to observe that exposure to loud sounds over time consistently leads to hearing damage. Just like they don't need to deliberately kill people in automotive crash tests to learn how to make safer cars, or deliberately kill people to test body armor efficacy, etc - they can review existing data from real-world events, as well as apply an understanding of physiology to better interpret and inform their conclusions. This is how real science and engineering works; it isn't the absolute black-and-white scientism you may find online.

For more, the US NIH has a Noise-Induced Hearing Loss (NIHL - this is the specific ailment/condition generally caused by exposure to loud sounds constantly) web page: https://www.nidcd.nih.gov/health/noise-induced-hearing-loss
There's also a similar page from the US CDC:
https://www.cdc.gov/ncbddd/hearingloss/noise.html
Wikipedia has a pretty complete page on it too:
https://en.wikipedia.org/wiki/Noise-induced_hearing_loss (this cites to a number of peer-reviewed sources and books, some of which appear to be available online - go ahead and blindly dismiss "because its Wikipedia" but there's an easy entry point into some further literature for you)
You might also try using Google Scholar with keywords like "Noise Induced Hearing Loss" or "NIHL" or "Acute Acoustic Trauma" and you may want to focus that on journals that have a focus on audiology, environmental/occupational safety, or construction/industrial engineering, since these are places where the topic is much more prevalent.

A lot of what's going to be published in a journal or book source will probably be behind a paywall or may not even be available in an entirely electronic form (e.g. an anatomy text-book may be easier to find in print). If you have institutional access to something like LexisNexis or ProQuest that will probably make life a lot easier. There *are* researchers doing work on this, but you won't find many of them working in electrical/audio engineering - they tend to be medical doctors or audiologists or similar. Every now and again a study will be done about NIHL in teenagers and may be picked up by conventional news sources (e.g. The New York Times) usually ending up in an article along the lines of "kids these days..." but I think most of the work being done focuses on noise exposure in industrial or commercial scenarios (like factory workers or orchestra performers).

Here's a single example (harvested from Wikipedia's citation section) of a peer-reviewed, published paper on NIHL that analyzes factory workers, did not require unethical mutilation of human subjects, and was written by audiologists: http://applications.emro.who.int/im.../Int_J_Occup_Environ_Med_2012_3_3_136_144.pdf (you may notice this paper has an incredibly narrow topic - again this is how actual scientific publishing works, and you aren't likely to find an encyclopedic style overview of a "big" topic like NIHL, but instead will see very narrow pieces of work that build together to support the larger whole).
Here's a broader meta-analysis from the CDC on the topic (also harvested from Wikipedia's citations), prepared by researchers at the US NIOSH:
https://www.cdc.gov/mmwr/volumes/65/wr/mm6515a2.htm


This is a well accepted reality that continued exposure to loud noises (above 80-85 dB - I've seen both values, usually given with an 8 hour/day exposure limit) will result in hearing damage - psuedoskepticism really has no place in this discussion.

Since the CCOHS piece wasn't linked, here it is:
http://www.ccohs.ca/oshanswers/phys_agents/exposure_can.html

Moving into a more Head-Fi focused source, Tyll wrote an article about noise-induced hearing loss for InnerFidelity called "Loud Music Sucks!" a while ago, which you can read here:
https://www.innerfidelity.com/content/loud-music-sucks

 

[stalepie]

Thanks. That PDF (http://applications.emro.who.int/im.../Int_J_Occup_Environ_Med_2012_3_3_136_144.pdf) seems a little lame though. Just a questionaire to 20 people about their feelings from the last 10 years. Not even a high sample group.

 

[obobskivich]

Thanks. That PDF (http://applications.emro.who.int/im.../Int_J_Occup_Environ_Med_2012_3_3_136_144.pdf) seems a little lame though. Just a questionaire to 20 people about their feelings from the last 10 years. Not even a high sample group.

Again, this is how legitimate research is conducted. You aren't going to see some 43,000 page study that went out and did intensive medical evaluation of 400,000 participants and went through 61 years of constant re-writes before being allowed to publish. Scientism isn't how actual practitioners do their job. I don't really understand what your purpose for this thread is beyond expressing psuedoskepticism towards an established and accepted fact - loud noise will hurt your ears, period, the end.

 

[stalepie]

I don't know what you're going on about, but I am interested in individual differences in hearing loss or how some people's ears seem to be stronger or less susceptible to damage.

 

[obobskivich]

I don't know what you're going on about, but I am interested in individual differences in hearing loss or how some people's ears seem to be stronger or less susceptible to damage.

That's very different than "is there any proof that loud noise causes hearing damage." Would've been much easier to start here. Either way, I'll still go back to what I said previously - Google Scholar will probably be the best way to query something like this, but most of what you find will probably be behind a paywall (this is just the nature of things). The numbers from OSHA/CCOHS/etc saying 80-85 dB are the exposure limits are the result of averaging/extrapolation from data, and are meant as guidelines for human exposure, so while there may be some minor degree of individual variation, I would not at all expect it to be like "well there's Jimmy, and Jimmy can withstand 140 dB sustained forever and has no problems" and instead it might be like "well, Jimmy worked at 85 dB for 8 hours and 10 minutes a day and didn't receive hearing loss for 6 months of that exposure, but Frank did it for 8 hours and 3 minutes a day and received hearing loss after 5 months and 28 days" or something more like that. But ultimately if you want to find that, do your own digging into the available literature (you'd want to find studies on hearing loss, which is probably what prompted your original question, and then look at their data and see what, for example, their confidence factors, correlation coefficients, standard deviations, etc look like (if that stuff is published)) - tools exist to facilitate that kind of inquiry but it will probably require significant digging into monetized databases (and maybe even going out and emailing an author of a study - most academics are pretty willing to discuss their work as long as you're respectful of their time). That is, again, not what you originally asked though. Phrases like "some people's ears seem to be stronger" are highly dubious and absolutely not "scientific" - you'd have to refine that to a more narrow and directed query.

 

[gregorio]

I am interested in individual differences in hearing loss or how some people's ears seem to be stronger or less susceptible to damage.

Not sure where you got that from, all people's ears are susceptible to noise induced hearing loss, I've never seen any evidence of anyone particularly less susceptible than everyone else. As Obobskivich suggested, do a search for scholarly articles on Google. There are literally hundreds of studies of noise induced hearing loss covering numerous different circumstances; specific age groups, specific recreational activities (such as listening to portable music devices, going to concerts, etc.), specific occupations, etc., from all over the world and covering many decades.

G

 

[stalepie]

Well there are muscles in the ear, such as Tyll said in that article he linked, Tyl" wrote: "When you are exposed to loud sounds, small muscles (stapedius and tensor tympani) in your middle ear tense to increase the mechanical impedance of the system of small bones (oscicles) that move vibrations from your eardrum to your inner ear." But with muscles some people are stronger than others. They have different potential, or using their muscles also makes them stronger. It is also interesting to me that when a bodybuilder pumps iron he is tearing his muscles, breaking it down I've heard, and then it has to repair. Perhaps there is some correlation here with the muscles in the ears. It also occurred to me that eye damage seems to occur so differently, and less common from environmental exposure, as we don't normally think of many people losing their sight from staring at the sun or nuclear explosions or TVs too much -- not really -- not in the same worried sense we do with hearing loss and loud sounds, as a common thing.

Anyway thanks for the response and I won't pursue it further. Sorry to bother. I will "use Google."

 

[gregorio]

Tyl" wrote: "When you are exposed to loud sounds, small muscles (stapedius and tensor tympani) in your middle ear tense to increase the mechanical impedance of the system of small bones (oscicles) that move vibrations from your eardrum to your inner ear."

Yes, that's called temporary threshold shift (TTS).

But with muscles some people are stronger than others. They have different potential, or using their muscles also makes them stronger. It is also interesting to me that when a bodybuilder pumps iron he is tearing his muscles, breaking it down I've heard, and then it has to repair. Perhaps there is some correlation here with the muscles in the ears.

That depends to what degree the bodybuilder damages those muscles. Too much damage and the repair will never be quite as good as before the damage. Also, with bodybuilders we're talking about relative massive muscle groups, not the tiny, delicate muscles found in the ears. In the case of hearing, too many or too much TTS's gradually (or immediately in more extreme noise cases) stops being temporary and becomes PTS (permanent threshold shift), that's permanent hearing damage and a surprising number of people have it, many of whom don't realise it and that number is increasing, even amongst children and teens. Again, many studies bare this out, as you'll see by doing a google scholarly article search. As a further hint, when you find a study/paper applicable to what you're looking for, head for the "references" section at the end, that will give you another bunch of papers/studies related to that paper.

G

 

[obobskivich]

That depends to what degree the bodybuilder damages those muscles. Too much damage and the repair will never be quite as good as before the damage. Also, with bodybuilders we're talking about relative massive muscle groups, not the tiny, delicate muscles found in the ears. In the case of hearing, too many or too much TTS's gradually (or immediately in more extreme noise cases) stops being temporary and becomes PTS (permanent threshold shift), that's permanent hearing damage and a surprising number of people have it, many of whom don't realise it and that number is increasing, even amongst children and teens. Again, many studies bare this out, as you'll see by doing a google scholarly article search. As a further hint, when you find a study/paper applicable to what you're looking for, head for the "references" section at the end, that will give you another bunch of papers/studies related to that paper.

G

To add to this excellent point - it isn't the muscles that are actually being "damaged" or "torn" in hearing loss so its a false equivalency to use the "bodybuilder" example - its the hair cells of the cochlea that are damaged (http://www.agius.com/hew/resource/nihl.htm explains it briefly), so there is no capacity to "train like a bodybuilder" here (and if there was, there'd be significant literature about it, instead of a multi-decades long consistent "loud things are bad for your ears" message - this isn't some conspiracy, and like I said, psuedoskepticism isn't the right answer here). Consistent exposure to loud noises consistently results in hearing loss, not "getting buff" and somehow being able to overcome loud noises. The muscles contracting at the ear (the acoustic reflex) is a protective mechanism of the body, just like throwing up when you ingest something nasty or sweating in the heat. Recovery from TTS is actually given some treatment on Wikipedia (it has citations too) - https://en.wikipedia.org/wiki/Auditory_fatigue#Recovery

 

[castleofargh]

being less susceptible under specific conditions probably happens, simply because humans are just different enough in most ways for some variations to exist. we could imagine that some people get the protection mechanism to be triggered at lower or louder volume levels, under very very specific loudness levels maybe that could result in difference? I don't know if in real life conditions it would matter significantly though.
on the other hand, how long the muscle handling the eardrum dampening can hang on before getting tired, maybe that does make a difference in the long run. maybe someone simply has more cells so it takes more time for him to really lose a frequency? maybe someone has ears that are simply not as efficient from the start, so wound waves aren't transmitted as efficiently inside the ear and don't reach the same levels? maybe it's about getting some proper rest from time to time for the muscle to relax. maybe the loss is mainly at specfici frequencies and the person doesn't really notice? many factors might end up making it look like someone doesn't suffer as much from loud noises, but I wouldn't count too much on having an actual resistance against loudness.

I've spent a few year around guys working in loud environments(trains), and as far as I could tell the general pattern for people with strong loss compared to the last medical visit, always seemed very logical and predictable. those with the worst results were clearly doing the worst stuff. not putting a hand to cover the ear next to where they would empty the compressed air(when a clear process exists specifically to reduce ear damage, there is even a thing called a silencer that almost nobody uses...). they would stop working only to go put on the radio to 11. spend the week-end hunting, mowing the grass and other "quiet" stuff like that without ever using any kind of protection or getting 20mn of quiet during the day. nobody could have looked at the way those guys lived and think they had bad luck and weak ears. they were only getting the consequences of how they lived.
maybe you can find a few exceptions because of something weird in their body, like why we're not all equals when it comes to cancer or diabetes or playing tennis. but if you're thinking about training your ear to resist loudness, that's a dumbass idea and most likely a dangerous one.

as for vision, everybody should know better than to look directly at the sun, or go skiing without googles and stuff like that. maybe we're not doing enough active prevention because we expect parents to do their damn job? maybe it's because in many cases just stopping the cause of the problem is enough to get better(as most UV damages will be superficial)? IDK. I'm guessing it might depend on where we live.

 

[gregorio]

being less susceptible under specific conditions probably happens, simply because humans are just different enough in most ways for some variations to exist.

Agreed, I'd be very surprised if there wasn't some variation from person to person. It's well known/documented that there's significant variation even in the same person; with age the muscles controlling the acoustic reflex harden and the ear cannot adjust as efficiently. That's why older people are far less tolerant of loud music/sounds than teenagers.

... it isn't the muscles that are actually being "damaged" or "torn" in hearing loss so its a false equivalency to use the "bodybuilder" example - its the hair cells of the cochlea that are damaged

With my limited knowledge, hearing damage relates to a number of different conditions. NIHL can be gradual or acute, includes cilia death and can include tinnitus, nerve damage and PTS; a TTS (acoustic reflex) become permanent. PTS can be quite pernicious because after a TTS event the ear recovers but may not totally recover, resulting in a small PTS which isn't noticed. Subsequent TTS events can result in further, cumulative PTS's to the point of it becoming noticeable but because of the gradual cumulative effect of these small PTS's the damage can be quite severe before it's noticed. There's a lot of concern currently about the use of portable music players by youngsters and a possible epidemic of NIHL.

G

 

[bigshot]

Narrow spikes in the frequency response in the wrong place can cause hearing damage even without triggering the flinch effect. That's why even if the perceived volume level is the same, you're more likely to incur damage at a concert where the response is ballparked than it is at home where you've flattened out the response. A narrow spike can jump to a high level without making the overall sound seem louder.