Reliability of hearing protector sound attenuation measurements at 63 Hz

摘要

In Europe as well as in other parts of the world the sound attenuation of hearing protectors is determined according to the procedure described in ISO 4869-1:1990. The test frequency 63 Hz is optional, but often included in product type examination test reports and certificates. Since the dynamic range of hearing decreases and the masking from physiological noise increases with decreasing frequency it has been questioned whether the test frequency 63 Hz is relevant as a descriptor of the product performance. This presentation will discuss the reliability of sound attenuation measurements at 63 Hz and present test-retest data from a 16 subject test panel that suggests that under well-controlled test conditions the reliability of sound attenuation results for an earmuff are poorer than those found at the standard test frequency of 1 000 Hz.