Abstract

Impact noise exposure assessment does not take into account concurrent continuous noise exposure. The elucidation of the effects of mixed noise exposure is therefore necessary.

Auditory fatigue was measured in humans before and after various types of noise exposure.

At low levels of impact noise, the effects of the two types of noise are additive. At higher levels, continuous noise exposure may act synergistically.

An integrated approach to noise exposure which takes both types of noise into account is essential. Other provinces, including the province of Ontario, have used this study as reference material in the drafting of their regulations. As a result of questions raised during this study concerning the influence of the average sound spectrum of impact noise, a specialised sound generator was developed (RS-83-33).