Hearing protection and speech intelligibility of two nonstandard inflight communication headsets

This study evaluated the hearing protection and voice communications effectiveness of two standard earmuff hearing protectors modified to function as voice communications headsets. Both modified units contained the AF standard H-143 inflight receivers and the M-87 noise cancelling boom microphone. Hearing protection and voice communication performance of the modified units were compared to those of the H-157 headset at four intensity levels of a noise spectrum that was generally flat from 63 Hz to 5000 Hz (80, 95, 105, 115 dB 20 microPa. The results showed that the H-157 headset provided more hearing protection than either of the modified headsets, especially in the higher frequencies. The modified headsets provided better speech intelligibility than the H-157 headset. Wearability problems were noted with the modified headsets which may become a problem in the operational situation.