Abstract
The American Conference of Governmental Industrial Hygienists has proposed a Threshold Limit Value for Noise. The limit for broad band noise would be 92 decibels, as measured on the A-scale of a sound level meter (dBA), for exposure of 4 to 8 hours per day; 97 dBA for 2 to 4 hours; 102 dBA for 1 to 2 hours; and 107 dBA for less than 1 hour. The limit for narrow bands of noise or pure tones would be 5 decibels lower than that for broad band noise. A limit of 140 decibels peak sound-pressure level for impulsive or impact noise is recommended.
