Study Links Personal Music Players To Hearing Loss 405
fprintf writes "A recent NY Times article discusses links between personal music players and hearing loss. This is not anything new; personally, I have hearing loss from listening to my Sony Walkman cassette player many years ago. However, given the widespread use of the personal music players, I see people using earbuds everywhere; is there a technical solution to the potential danger?"
SCENIHR Report (Score:5, Informative)
But it also threatens permanent hearing loss for as many as 10 million Europeans who use them, according to a scientific study for the European Union that will be published Monday.
I don't know if this is the report but the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) released a report on this in June [europa.eu] [PDF Warning!]. It's not as long as it looks, about a quarter of the pages are citations to other studies. It looks quite comprehensive. It's important to note that this is not a simple thing to study. The report points out several times that your age and daily exposure and anatomical structure all play an important role in what you can tolerate before experiencing hearing loss.
The abstract from that report:
Exposure to excessive noise is a major cause of hearing disorders worldwide. It is attributed to occupational noise. Besides noise at workplaces, which may contribute to 16% of the disabling hearing loss in adults, loud sounds at leisure times may reach excessive levels for instance in discos and personal music players (PMPs). It is estimated that over two decades the numbers of young people with social noise exposure has tripled (to around 19%) since the early 1980s, whilst occupational noise had decreased. The increase in unit sales of portable audio devices including MP3 has been phenomenal in the EU over the last four years. Estimated units sales ranged between 184-246 million for all portable audio devices and between 124-165 million for MP3 players.
Noise-induced hearing loss is the product of sound level by duration of exposure. In order to counteract noise-induced hearing loss more effectively, a European directive "Noise at Work Regulations" taking effect starting February 2006, established the minimal security level at the equivalent noise exposure limit to 80 dB(A) for an 8 hour working day (or 40 hour working week), assuming that below this level the risk to hearing is negligible. The 8-hour equivalent level (Lequ,8h) is a widely used measure for the risk of hearing damage in industry, and can equally be applied to leisure noise exposures. The free-field equivalent sound pressure levels measured at maximum volume control setting of PMPs range around 80-115 dB(A) across different devices, and differences between different types of ear-phones may modify this level by up to 7-9 dB. The mean time of exposure ranges from below 1 hour to 14 hours a week.
Considering the daily (or weekly) time spent on listening to music through PMPs and typical volume control settings it has been estimated that the average, A-weighted, eight hour equivalent sound exposures levels (referred to "Noise at Work Regulations") from PMPs typically range from 75 to 85 dB(A). Such levels produce minimal risk of hearing impairment for the majority of PMP users. However, approximately 5% - 10% of the listeners are at high risk due to the levels patterns and duration of their listening preferences. The best estimate from the limited data we have available suggests that this maybe between 2.5 and 10m people in EU. Those are the individuals listening to music over 1 hour a day at high volume control setting.
Excessive noise can damage several cell types in the ear and lead to tinnitus, temporary or permanent hearing loss (deafness). Published data indicate that excessive acute exposures to PMPs music at maximal or near maximal output volume can produce temporary and reversible hearing impairment (tinnitus and slight deafness). Major discrepancies exist between the results of the studies on permanent noise-induced hearing loss in PMP users, with both, positive and negative studies published. Tinnitus and hearing fatigue may occur more frequently in teenagers chronically exposed to music, including PMP users, than in non-users.
In addition to auditory effects harmful, lasting and irreversible non-a
YES! (Score:4, Informative)
Should be: Nothing to see here, move along (Score:5, Informative)
Seriously, this is a "Ric Romero" report to borrow a Fark term: High volumes for extended times cause hearing loss. News at 11. The only reason why portable players are any more significant in this than anything else is that since you can take them with you all the time, you have the opportunity to do the wrong ting more often.
There is no technical solution, because the maximum output of a player depends on the headphones plugged in to it. Plug in some low impedance IEMs with high efficiency, and you'll find that it may be able to produce SPLs in excess of 120dB no problem. Plug in some low efficiency high impedance professional phones, and you may find it struggles to do even 70dBSPL. Thus you can't set up some sort of magic limit that'll be ok for everything. A limit that would protect your ears with Shure IEMs would be damn near inaudible on Sennheiser 580s.
There are two things you can do to protect yourself:
1) Turn the volume down. Really, it is that simple. Just don't set the things so loud and it isn't a problem. That is ultimately what you have to do.
2) Get phones that isolate better. The reason why some people abuse the volume dial is to try and drown out noise. Don't do that. Block the noise instead. Instead of cheap earbuds, invest in some good IEMs. Yes, it is going to run you $100-300. Deal with it. If you can drop hundreds on a iPod, you can drop hundreds on good phones to go with it. Then take the time to get the right fit for your ears so they create a good seal. That will attenuate sound nearly as much as good earplugs.
With good earphones, you should be able to keep the volume down and still enjoy the music. You keep the volume down, there's no problem.
Loud noise, no matter what the source, is dangerous to your hearing especially over long periods of time. Playing loud music on speakers is just as bad as headphones. Only difference is you can do it all day on headphones and nobody will yell at you. Just turn that shit down to a reasonable level. If you can't because things are too noisy, get better headphones to block the noise.
Signal to Noise (Score:3, Informative)
Some people turn up their music so that it really is loud in their ears. Most people, however, turn it up so damn loud to get the desired signal (music) above the background noise: car traffic, car interiors, subways, crowds, airplane cabins. When the noise floor is already pretty loud (50-80 dB), you have to pump up the volume on that music player ever higher to be able to "hear" it. There's psychoacoustics involved beyond just the overlapping audio sources. Music played that loud, even if it doesn't seem loud (because it's only, say, 10-20 dB above the noise floor) is actually well above the NIOSH limits on what can be a safe prolonged exposure. Result: hearing loss.
The only real solution that will allow you to hear your music (or cellphone, for that matter) without having to crank it up to damage-inducing volumes, is to reduce the noise floor. This can be done pretty easily with passive noise attenuation - padded headphones can give you a few dB of attenuation of low frequencies, and tens of dBs at higher frequencies. Earbuds offer almost no passive noise attenuation, although they could do a little bit if they sealed off the ear canal. Unfortunately, big padded headphones are a lot more conspicuous than little white earbuds, and they didn't come with your iPod, and you can't easily stow them in your pocket.
The other alternative is active noise reduction, like the Bose QuietComfort. You can even find noise-cancelling earbuds, although they tend to not work as well. Unfortunately, ANR doesn't come cheap if you want something that actually works and doesn't ruin your listening experience. Still, digital signal processing with low-power components will probably make this more widely-available in the future....if you can still hear anything by then.
Re:Bone conduction anyone? (Score:3, Informative)
Yes. You hear because the hair in your inner ear vibrates. You get hearing loss when those hairs are damaged. Whether that sound comes from your eardrum or through your skull, doesn't matter.
Here is the simple solution (Score:5, Informative)
The real problem is to determine whether you are playing the music too loudly for your safety. Here is how to get a good idea of the harm you are doing ...
1. Find something like a watch or other device that makes a very quiet sound. Find a distance where you can just make out the sound.
2. Listen to your music source at your customary level for 15 to 30 minutes or longer if that is your habit.
3. Set up the conditions in (1) above and see if you can still hear the sound. If you can, you are probably not harming your hearing ... If not, then you have a temporary threshold shift and you have already done some small amount of damage to your hearing. The greater the shift, the greater the damage.
4. More likely, if you listen to loud music or listen in inherently noisy places, you will notice the threshold shift in daily life. background noises disappear, which is like 40-50dB SPL, and definitely a problem.
These hearing conservation links explain a lot [okstate.edu] Mp3 players are not the only culprit, driving with wind noise in your left (or your passenger's right) ear, circular saws and construction tools, and other sources of noise are damaging. Music is different in that it can not be blocked but can be controlled.
If you don't protect your hearing from loud sound, sooner or later a notch will start to form in your ear's frequency response curve. The notch will be centered around 4000 Hz, right where high frequencies get really high, and useful too. That notch widens above and below until it impacts 2KHz or even lower. Somewhere along the way, the detectors in the ear will get so damaged that they start detecting sound non-linearly and harmonic and intermodulation distortion arise. Finally, when they get injured some more, they start to fire "all or none" and even moderately loud sounds can be painful. That is called recruitment and is really damaging to hearing and sanity.
I hope this information is useful to readers. I hate to see people lose hearing when it is so unnecessary in most cases.
If you think your hearing is going bad, see an audiologist or ear doctor or both, soon. Most processes can be stopped, and believe me, you will be glad you at least stopped the damage.
I am pushing 60 years old, have used threshold shift changes to remind me to protect my hearing, and still have no noise notch in my good ear. My other ear was damaged by childhood infections and is mostly useless so I guess having only one ear made me more careful.
IEMs / Canalphones (Score:3, Informative)
What you want are "in ear monitors" a.k.a. "canalphones." These are like earplugs with a sound transducer in the center. They attenuate ambient noise by up to -23dB, depending on the model. With that much attenuation, you don't have to turn them up to dangerous levels to hear them, even on the subway. They're designed for musicians so they can hear what they are playing on stage without blasting it over everything else. They coil up into a pouch that fits into your pocket. Plus, they sound very good. Some have reference quality sound and will sound better than any other pair of headphones available unless you listen in a silent room.
Downsides: if you can't handle a plug in your ear then you can't use them, but you can get a custom molded earpiece that makes them very comfortable. Also, the cable can conduct handling noise into your ear, though this isn't a problem with the "pro" versions that hook over your ear or the ones with very thin and pliable cables.
The biggest downside is you cannot hear anything around you with them on, which can make them very dangerous to use in traffic and other situations.
Manufacturers include Etymotics, UltimateEars, Sensaphonics, Shure, and probably a couple others. I've been a big fan of the Etys/Sensaphonics. I recommend the Etymotic ER-6i. Get the ER-4P if you have more money to spend and want better sound. Both of these are high impedence models that work well with an ipod or laptop without a separate high current amplifier.
Once you start using these things you will be spoiled for anything else.
Re:Turn down the volume (Score:2, Informative)
I'd suggest that you go speak to an audiologist [wikipedia.org], who actually does have the background and equipment for that.
Re:Turn down the volume (Score:4, Informative)
I recently ended up on a party where the music was so loud, that I contacted a senator with the idea of a legal obligation to make earplugs available at dancings and parties. When I say loud, I mean that my t-shirt was moving with the beats.
He's also a doctor, so I figured he would realize the dangers. His answer was very positive, and gave me some further information on the damage done: apparently, damage done by short term exposure can heal, but long term exposure is permanent. He was also working on legislation to limit the maximum volume of mp3 players.
This is a lingering problem that will manifest itself in the next decades when hearing implants will become much more common.
Personally, I cecame much more aware of the problem after I spoke to a friend who has worked on sound measurements of jet fighter his whole life, and now he hears a loud, high-pitched tone 24/7, driving him crazy sometimes. The "solution" is to have two hearing aids, not to amplify the sounds around him, but to inject white noise. This drowns te tone he hears partly (our brains cancels out white noise), making his life more or less bearable. But I think it is still hard for him. Just imagine how it must feel and you'll realize it must be.
So yes, this is a real problem, and everybody should at least be aware of it.
Re:Turn down the volume (Score:3, Informative)
Its called tinnitus. Patrick Stewart is a pretty well known case. Band musicians tend to get it from playing in front of deafening monitors all the time as well. Don't think there is much that you can do about it. Limiting the volume of mp3 players would be a terrible idea. My cheap insignia is only really listenable between 30-40 on the dial. 40 is the max. Maybe I am going deaf too..... ;)
Re:Turn down the volume (Score:3, Informative)