TESTEAR—An Electronic Dummy for the Physical Measurement of Sound Attenuation of Hearing Protectors

Abstract

The psychophysical testing and evaluation of conventional and communication-type hearing protectors continues to present a major problem in industry, engineering, and Government procurement. Testing is time-consuming, costly, impractical, and not always reliable for routine engineering applications where outcome of such tests cannot be awaited. TESTEAR provides an objective testing method by which the attenuation characteristic of hearing protectors or microphone noise shields can be plotted automatically in a few minutes from a high intensity sound source generating pure tones, bands of noise, or even from actual noise in any given environment. Because the test signals are at high sound-pressure levels, TESTEAR does not require expensive anechoic test rooms. For the same reason, the recorded data are more representative of the performance of hearing protectors under actual field conditions. Comparative tests conducted with 30 subjects with the threshold-shift method and with TESTEAR physical method produced attenuation curves showing close correlation between methods. TESTEAR does not require instrumentation other than that normally found in the acoustics laboratory.