[Hearing damage caused by impulse noise]

Methods for judging the danger of hearing impairment caused by continuous noise are known and have been included in standards. There are no equally accepted criteria to distinguish between dangerous and harmless impulsive noise. For this reason, a mobile measuring system has been developed, that can determine and record parameters of impulsive noise in industrial environments. The parameters were chosen with respect to the properties of the human ear, and to provide an intercomparison of currently used or proposed measuring methods. In one case, the frequency response of the outer and middle ear is simulated electrically in order to evaluate the signal that would reach the inner ear, where damage usually occurs. The data collected at the operators position of industrial machines will be correlated with the corresponding audiometric evaluation of hearing damage conducted by SUVA (Swiss National Insurance Fund), in order to find damage risk criteria for impulsive noise.