A Parametric Evaluation of the Equal Energy Hypothesis
A current issue of debate is whether the effects of impulse/impact noise are the same as the effects of continuous noise. Passchier-Vermeer  reviewed several demographic studies and reported that for equal amounts of sound energy, exposure to noises that had impulsive components produced larger amounts of hearing loss than the exposure to continuous noise. A series of laboratory studies, using an animal model of hearing loss, have shown that exposure to impulse noise of 140 dB or greater produces lesion in the cochlea that are probably mechanical in nature [2,3] and the pattern of recovery of auditory sensitivity following the exposure is often complicated; i. e., there is an initial period of recovery of sensitivity, then a reversal to higher levels of loss at 6 to 12 hours post-exposure, then a more gradual return to either a permanent hearing loss or to pre-exposure levels of auditory sensitivity [4,5].
KeywordsHearing Loss Noise Exposure Impulse Noise Auditory Sensitivity Sound Level Meter
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