Important Links for Sound and Noise|
OSHA United States Department of Labor http://www.osha.gov/SLTC/noisehearingconservation/
OSHA United States Department of labor eTool Technical Manual http://www.osha.gov/dts/osta/otm/noise/
Sound and Noise Exposure Facts|
Any exposure to noise above 85dB can damage the human hearing; as a rule of thumb, the ambient sound is too loud if you can not carry on a conversation without raising your voice. Occupational noise
Understanding Sound and Noise Levels|
Weakest sound heard
Whisper Quiet Library at 6'
Normal conversation at 3'