Hearing experts worry that the increasing popularity of MP3 players may lead to widespread hearing loss. The concern is that with increased sound quality, people are listening to music louder and longer.
Music and loud noise have been known to cause hearing loss for centuries. Noise exposure causes hearing loss by damaging the hair cells in the cochlea of the inner ear. The hair cells transmit sound information to your brain. Hair cells can recover from temporary damage, but loud and frequent noise can permanently damage them. A good way to understand the temporary damage is to compare it to walking on grass. If you walk on a lawn occasionally, you won’t damage it because the grass has a chance to recover it. If you trample the grass constantly, it loses it ability to bounce back and becomes permanently damaged. Damage to the hair cells in the ear happens the same way.
The decibel (dB) is the unit used to measure sound levels. The cutoff for acceptable risk for workplace noise is 85dB. The level of negligible risk considered to be 75dB or below. Many studies have looked at personal stereos and, in general, listening levels tend to be below the 85dB risk cutoff. A study in the April 2005 International Journal of Audiology looked at noise exposure levels from personal stereo use and determined that the average continuous noise exposure level was 79.8dB, with a statistically significant difference between males and females, of 80.6dB and 75.3dB respectively. Basically, most people stay within a safe range, but it is important to watch the volume, because some personal music players reportedly can produce levels as high as 120dB.
Here are some other estimates of noise levels:
- 30dB Whisper
- 60dB Normal conversation
- 80dB Ringing telephone
- 90dB Hair dryer / power lawn mower
- 93dB Belt sander
- 96dB Tractor
- 98dB Hand drill
- 108dB Continuous miner
- 110dB Chain saw
- 114dB Hammer drill
- 120dB Ambulance siren
- 140dB Jet engine at takeoff
- 165dB 12-gauge shotgun
- 180dB Rocket launch
- 194dB Loudest tone possible
So … the bottom line is that if you are driving an ambulance to the shooting range, you should use ear protection. As for the iPod, we love everything that Apple makes so we hope that they aren’t dangerous. We suggest that you keep the volume low, but even if they find out that iPods cause hearing loss, imaging the cool hearing aids that Steve Jobs will create.
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"Do iPods cause hearing loss?" was posted on Monday, January 21st, 2008 at 11:51 pm.