Impulse noise and occupational hazard: regulation, knowledge and measurements.

Along with continuous noise, impulse noises are a risk for hearing and are subject to regulatory limits based on the equivalent and peak sound levels. The present limits are based on strong assumptions (given effect for an energy equivalent dose, release of the acoustic reflex of the ear, assumed waveform of the noise) and do not necessarily meet all the problems related to impulse noise exposure. A study was undertaken to assess how the current regulation is able to preserve the hearing of exposed workers. A bibliographic work enabled to take stock of knowledge about the risks induced by these sounds in the workplace, the relationship between their properties and hearing hazards as well as potential research opportunities. In addition, a measurement survey was conducted on sites identified as prone to this kind of exposure. The goal was to identify in situ the impulse noise typologies, to observe the case of combined exposure with continuous noise and to identify personal protection strategies. Bringing together these two approaches will enable to assess whether – for a given exposure level - the hearing of workers exposed to a realistic impulsive environment is more in danger than the hearing of workers exposed to continuous noise and if so, what solutions/research opportunities are possible.