Accession Number:



Research on Modelling the Effects of Personal Hearing Protection and Communications Devices on Speech Intelligibility in Noise

Descriptive Note:

Contract rept.

Corporate Author:


Report Date:


Pagination or Media Count:



The effects of two advanced level-dependent communication devices on face-to-face speech intelligibility in military noises were investigated. Devices were the NACRE QuietPro and the PELTOR Powercom Plus. Noises from the LAVIII and Bison light-artillery vehicles were reproduced in a noise simulation room at 80-95 dBA. Over 45 subjects covering a wide range of hearing profiles from normal hearing to severe hearing loss were tested using sentences from the Hearing-In-Noise Test HINT. When used as passive devices with the electronics powered off, the two devices performed as expected from conventional hearing protectors having the same amount of attenuation. In this mode, there were large performance differences among subject groups in terms of the effects of wearing the devices compared to unprotected listening. However, when used in active talk-through or surround mode, both devices showed large speech intelligibility benefits over the passive mode and demonstrated a level of performance often exceeding that in unprotected listening. The subject group with the most impaired hearing benefitted the most from the active mode. The findings indicate that the current technology of high-end tactical communication devices could provide substantial benefits in situational awareness during noisy military operations for all hearing grades.

Subject Categories:

  • Protective Equipment
  • Voice Communications

Distribution Statement: