MOST COMFORTABLE LOUDNESS SHIFT AS A MEASURE OF SPEECH ATTENUATION BYHEARING PROTECTORS

The feasibility of using most comfortable loudness (MCL) as a real-wor ld measure of speech attenuation introduced by hearing protection devi ces (HPDs) was studied. The authors compared three insert HPDs and an earmuff under three test conditions: (a) monaural earphone listening, (b) binaural earphone listening, and (c) sound field listening. The ea rmuff was used only in the sound-field condition. In addition, three s ets of fitting instructions were utilized. Twelve normal hearing subje cts participated. Results indicate that MCL shift can be used as a sim ple measure of speech attenuation provided by HPDs. The observed MCL s hifts were affected by the fitting instruction but not by the listenin g condition. Findings support the notion that MCL-based tests of speec h attenuation by HPDs can be conducted reliably both in sound field an d under earphones and may be a simple and valid tool for assessing cha nges in speech audibility due to the wearing of HPDs.