Abstract
The Occupational Safety and Health Administration (OSHA) has suggested permissible exposure to impulse noise, designating a maximum of 100 impulses for signals of 140 dB peak sound pressure level (SPL). Subsequently, for each 10 dB decrease in peak SPL (130, 120,110, etc.) the number of impulses may increase by a factor of 10. For impulse noises whose levels fall between these values, linear interpolation is not valid because of the logarithmic nature of the to decibel. This paper provides a formula (n=1016-P/10) to compute permissible exposure for impulses with peak SPL between the 10 dB intervals designated by OSHA. For convenience, a table is provided which gives the maximum number of permissible impulses for levels (in 0.5 dB steps) from 140 dB (100 impulses) to 112.5 dB (56 234 impulses). Given even the briefest possible duration, total impulses in an eight hour work day cannot exceed 57 600 since at that point sound, by OSHA's definition, becomes continuous rather than impulse noise.