A MULTIPURPOSE FACILITY FOR RESEARCH ON HEARING PROTECTION

Assessment of the efficacy of personal hearing protectors is based on a wide range of factors, requiring a diversity of experimental methodologies and acoustic test environments. This paper describes the development of a multi-purpose facility which complies with current Canadian and American standards for the measurement of the real-ear attenuation of hearing protectors. The facility also allows for a variety of experiments in auditory perception, including speech intelligibility and sound localization, known to be particularly relevant in the workplace. Two main features are: (1) an acoustic test chamber with a modular sound absorption system, and (2) computer-controlled signal presentation and subject monitoring instrumentation. As an application of the facility, the attenuation results generated using two psychophysical methodologies, a variation of Bekesy tracking and two-interval forced-choice, were compared for two insert hearing protectors (E-A-R formable foam and Bilsom Soft) and two earmuffs (E-A-R 3000 and Hellberg No-Noise). The difference due to method was not statistically significant. © 1990.