How many times have you come home from a rock concert with your ears ringing and your head throbbing, barely able to hear because of the blaring music? Overloud MP3 players can cause the same problems.

After you listen to loud music for a while, your hearing may seem dull. This is technically called a threshold shift and it can be temporary or permanent, depending on how loud the sound was and how long your ears were exposed to it. Both temporary and permanent threshold shifts can be caused by the same loudness. In temporary threshold shifts, your hearing may return to normal after a day or two.

Permanent hearing loss is different. You don’t notice the effects immediately, but after a while, it seems like everyone is speaking too quietly and you can’t hear.

How Loud is too Loud?

MP3 players and other personal music devices are the main causes of noise-induced hearing loss in teens and young adults. It is not the device that’s the problem here; it’s the user. Like many young people, maybe you abuse your ears by listening to music that is just too loud.
The question of what is too loud is totally subjective; what may seem comfortable for one person may be too loud for another. So how do you define a safe volume?

What’s Safe?

Sound level is measured in decibels (dB). Research shows that sound levels above 85 dB (about the sound level of a lawnmower) can be harmful with prolonged exposure. The louder the sound, the less time it takes for permanent hearing loss to occur. Sound levels in rock concerts can be as high as 104 to 112 dB–almost as loud as a jet aircraft on takeoff.

On the other hand, personal music devices are more insidious; though they do not appear to be as loud as rock concerts, they can in fact be almost as loud. The reason for this is that the sound is coming from headphones placed directly against the ear. Numbers on the headphone dial simply show how far from or close to the headphone’s maximum sound output you are. The dial is not an indicator of the sound level going into your ears. So you never really know what is loud but safe, compared with what is loud and hazardous.

A good rule of thumb is that if the music in your ears can be heard by someone else standing three feet away, or if people have to shout to get your attention, it’s likely the music playing in your ears is loud enough to harm you.

Moderation and responsibility are key in preventing premature hearing loss. Protect your ears and they will continue to provide you with listening pleasure so you can keep on rockin’.

Fred V. Matta, MClAud, Aud(C), is a clinical audiologist involved in the assessment, diagnosis, and treatment of childhood and adult hearing disorders in Vancouver.

Source: alive #293, March 2007