Measuring helmet sound attenuation characteristics using an acoustic manikin

Abstract

The sound attenuation characteristics of two military helmets were measured using an acoustic manikin as the test apparatus. The manikin results are compared to the results of attenuation measurements made on human subjects wearing identical helmets. The testing room and instrumentation were the same for both the manikin and human subjects. Procedures in ANSI S3.19-1974 were used in the real-ear attentuation at threshold (REAT) part of this study. The results are encouraging as they suggest that the manikin may be used in place of a panel of human subjects to evaluate the hearing protection characteristics of military head gear.

Binaural Recording Technology: A Historical Review and Possible Future Developments

“…Other problems at this time were the limited frequencyresponse and dynamic 13 The "artificial head" of Dickson and colleagues, and also the heads used by manyo thers to measure transmission loss of helmets or hearing protectors, are also known as acoustical test fixtures (ATF). They are often monaural devices and other very special requirements such as the transmission loss of the head itself or impedance changes due to the presence of the hearing protector are much more important than the fines tructure of the HRTF.T herefore, theya re mostly not artificial heads for binaural pick-up as understood in the current article and the reader interested in AT Fs may consult the specificl iterature [57,58,59,60,61,62,63,64,65,66,67]. In 1982 Richter et al [68] published results for plug-type hearing protectors using commercially available manikins (BK4128 eHMS II 4.n).…”

An acoustic head simulator for hearing protector evaluation. I: Design and construction

“…The fixtures used range from simple block designs (Brinkmann and Serra, 1982;Chillery, 1982) to more complex head simulators aimed at reproducing relevant properties of the human head (Flottorp and Quist-Hanssen, 1960;Russell and May, 1976;Osmundsen and Gjaevenes, 1981;Smith et al, 1982;Ivey et al, 1987). To date, however, the most comprehensive work on the subject has been reported by Schroeter and co-workers (Schroeter and Els, 1982;Schroeter and Poesselt, 1984;Schroeter, 1986;Schroeter and Poesselt, 1986).…”