by Neil Bauman, Ph.D.
A young man asked:
What is the safe range of sounds for human ears? How long can a person be in a dangerous range range before damage occurs? Are we talking about hours, minutes or just seconds?
The current wisdom is that sounds that always remain below 80 dB are safe for our ears and will not cause any damage no matter how long we listen to them.
Above that, OSHA has set the following rules for workplace exposure. You should take these guidelines for all noise exposure–whether it is recreational noise, traffic noise, workplace noise, or the noise you pump into your ears listening to iPods, MP3 players and related devices.
Here’s how it works. For each 3 dB (decibels) you increase the sound, you need to cut the time your ears are exposed to loud sounds in half. Here is what the maximum safe time and sound level chart looks like.
| 85 dB | 8 hrs |
| 88 dB | 4 hrs |
| 91 dB | 2 hrs |
| 94 dB | 1 hr |
| 97 dB | 30 min |
| 100 dB | 15 min |
| 103 dB | 8 min |
| 106 dB | 4 min |
| 109 dB | 2 min |
| 111 dB | 1 min |
| 114 dB | 30 sec |
| 117 dB | 15 sec |
| 120 dB | 8 sec |
| 123 dB | 4 sec |
| 126 dB | 2 sec |
| 129 dB | 1 sec |
Some iPods can produce sounds up to 117 dB–but how many people do you see wearing them for only 15 seconds? That’s how many people are damaging their ears if they have them cranked wide open.
If you want to be safe, and want to listen to your iPod for say 2 hours a day, then make sure you set the volume to limit the peaks to 91 dB or less, and for the other 22 hours in the day, you give your ears a rest and keep all sounds below 80 dB.