Performance evaluation method for high noise environment intercom headsets
Stelios M. Potirakis, Y. Moisiadis, Antonis Varagis · The Journal of the Acoustical Society of America · 2008
Intercoms' use in high noise environments (HNE) is typical since direct speech communication of individuals is difficult or even impossible. The headset selection for such an application is crucial since it serves both for noise attenuation and voice reproduction. It has been recently acknowledged in telecommunications (ITU-T/P.380) that headset electroacoustic measurements should be performed on head and torso simulator (HATS). However, in military applications where headsets are mainly used in HNE there is not a standard performance evaluation method but only for the earphone elements (MIL-PRF-25670B), thus excluding the acoustics of the earcup cavity, absorbing materials and face fitting quality. It is well known that the reproduced speech level should be of about 10 dB above noise level to achieve good intelligibility, so both sensitivity and noise reduction capability should be measured on a HATS to evaluate such a headset. In this work, a systematic methodology for measurement and performance evaluation of HNE headsets is proposed based on HATS. Critical aspects that may affect the test procedure, such as HATS response and the right headset placement are examined. Finally, a series of measurements prove the value of the proposed method. Large differences are revealed even for headsets following the same standard.