Measurement of the attenuation characteristics of nonlinear hearing protective devices using the auditory brain stem response.

The purpose of this study was to determine the feasibility of using the auditory brain stem response (ABR) as a method of measuring the attenuation characteristics of nonlinear hearing protective devices. Sound field ABRs were recorded from seven normal hearing subjects with and without hearing protection. Three hearing protectors (two nonlinear and one linear) were evaluated. Test stimuli, consisting of 4000-Hz tone pips, were presented in a sound field. Linearity and the amount of attenuation for each hearing protector were derived by comparing the protected and unprotected latency-intensity functions for wave I of the ABR. Results indicate that the ABR may be used effectively to measure the attenuation characteristics of linear and nonlinear hearing protectors for high-frequency impulse-type stimuli.