Posted by Bill on April 30, 2001 at 07:37:14:
In Reply to: What is a safe decibel level? posted by Phil on April 29, 2001 at 22:29:41:
When I taught in British Columbia, I found myself in a similar situation for 5 years. I had a 24 X 32 foot bandroom for a high school band of up to 50 members. I also had a stage band , a rock band and a choir. Additionally, I taught one to three sections of Senior English. I was examined by a doctor and referred to a hearing specialist for an industrial hearing injury. He sent a technician to my job site. The Tech placed a meter on a strap around my neck before my first class and told me to wear it until the end of the day. At the end of the day the tech read the meter and discovered I was being exposed to 97.5 dB, average throughout the day which include lunch, an English class and a girls glee club class (with 22 members). There is no safe exposure limit for that level. 90dB is more or less safe for 3 minutes but, above 95 dB their rules allow no exposure. My room was sealed and posted against use.
My principal said they "would see what they could do about it and I should carry on." The janitor supervisor was directed to remove the posting sign. He called a study session and closed down the school for an hour. The principal withdrew the directive and called for the superintendent.
I suffered a 10dB hearing loss of frequencies between 1,000 and 2,000 cycles and it is permanent. In extreme conditions the damage will show up in that short a time (4 years). Usually the damage shows up much later. Ear plugs would not have been a solution for my case but might work for a pit musician. But you should not allow a sustained exposure over 85dB. You will be hurting yourself and I would have been damaging my students, one of whom was my son. If your meter was measuring this volume on your body, you are in trouble but if it was in front of you and your horn, it might not mean much. You should check the level at your ears.