Citation

Hashimoto M, Kumashiro M, Miyake S. Int. J. Ind. Ergonomics 1996; 18(2-3): 121-126.

Copyright

(Copyright © 1996, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

In industrial workplaces, it is widely believed that the use of hearing protectors interferes with communication and with the perception of warming signals. The objective of this study was to estimate effects of attenuation of the protectors on speech perception in noise. In the experiment, the intelligibility of monosyllables was assessed for ten normal-hearing adults, using three types of protectors with different attenuation characteristics. The speech materials were presented at two speech levels (65 and 85 dBA) in noise. The noise level was altered at signal-to-noise ratios (SNR) of 0, +5, and +10 dB. The results showed that speech intelligibility was significantly influenced by type of protector, speech level, and SNR. The interaction between these factors was statistically significant. The wearing of the earplug with decreased low-frequency attenuation resulted in less deterioration when the speech was presented at 65 dBA. On the other hand, such an earplug did not improve speech intelligibly as compared with other protectors when the speech was presented at 85 dBA. Therefore, the use of the protectors with decreased attenuation to improve speech communication for workers wearing protectors needs to be re-examined.