Silently, on the inside, I was laughing to myself as I read the worried statements and then read the calculated SPL measurements expected, when my normal listening level is about 123-127dB for music of an aggressive nature, and when I pegged the CEL 201 on it's 140dB scale 3 weeks ago while testing my new speaker layout.
I know I've lost a LOT of hearing in the past forty years since I've been involved with sound reinforcement, running FoH for rock bands, etc in the 80s and suffering from an as-yet unnamed mental illness that thrives on ridiculous amounts of bass.
Just a few references:
The Bridgeport Symphony's loudest measured crescendo: 105dB
Molley Hatchet concert: 114dB
I think 80-85 is quite safe... unless you're a Tibetan monk and hope to have perfect hearing to age 90.
120dB used to be called the "threshold of pain" and now, it has been reduced to "threshold of feeling", with 130dB being called the threshold of pain.
Here ya go- OSHA's Permissible Noise Exposure table from
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9735&p_table=STANDARDS:
" TABLE G-16 - PERMISSIBLE NOISE EXPOSURES (1)
______________________________________________________________
|
Duration per day, hours | Sound level dBA slow response
____________________________|_________________________________
|
8...........................| 90
6...........................| 92
4...........................| 95
3...........................| 97
2...........................| 100
1 1/2 ......................| 102
1...........................| 105
1/2 ........................| 110
1/4 or less................| 115
____________________________|________________________________
Footnote(1) When the daily noise exposure is composed of two or
more periods of noise exposure of different levels, their combined
effect should be considered, rather than the individual effect of
each. If the sum of the following fractions: C(1)/T(1) + C(2)/T(2)
C(n)/T(n) exceeds unity, then, the mixed exposure should be
considered to exceed the limit value. Cn indicates the total time of
exposure at a specified noise level, and Tn indicates the total time
of exposure permitted at that level. Exposure to impulsive or impact
noise should not exceed 140 dB peak sound pressure level."