Among the many kinds of pollution which besiege us today, noise pollution is often overlooked.

The human ear is a finely tuned mechanism able to distinguish over 1500 separate musical tones.

An important part of our hearing mechanism is the hair bundle found in the inner ear.  These hairs, called stereo cilia, convert the vibrations which hit the ear drum into an electrical nerve signal.  These messages are then relayed to the brain.

Recent work has shown that these ear hairs have the ability to regenerate.  They are totally replaced every two days.  Many rock music fans have reason to be thankful that these delicate hair bundles can regrow, because excessive noise will damage them.

Temporary hearing loss is associated with very loud sounds.  It’s now thought that one of the main causes of this transient deafness is damage to ear hair bundles.  The turnover rate of forty-eight hours needed for regrowth is about the same as the recovery time from noise-induced hearing loss.

It’s hoped that these findings will throw light on the development of hearing in newborn babies.  It may also explain why teenage rock fans sometimes have a hard time tuning back to the more subtle sounds of everyday life.

So next time you encounter a bedlam of sound, be thankful that nature has ways to protect your hearing from irreversible damage.

Bob