There is a thread
on another forum that is going over protecting your hearing.
Protect Your Hearing
Provided by National Institute on Deafness and Other Communication Disorders
Know which noises can cause damage. Wear ear plugs when you are involved in a loud activity.
110 Decibels - Regular exposure of more than 1 minute risks permanent hearing loss.
100 Decibels - No more than 15 minutes unprotected exposure recommended.
90 Decibels - Prolonged exposure to any noise above 90 decibels can cause gradual hearing loss.
How Loud is Too Loud?
Example noises and their decibel levels:
140 Decibels - rock concerts, firecrackers
120 Decibels - boom cars, snowmobiles
110 Decibels - chainsaw
100 Decibels - woodshop
90 Decibels - lawn mower, motorcycle
80 Decibels - city traffic noise
60 Decibels - normal conversation
40 Decibels - refrigerator humming
20 Decibels - whispered voice
0 Decibels - threshold of normal hearinghttp://health.yahoo.com/health/centers/hearing_loss/4