Calibration of an In-Ear Dosimeter for a Single Hearing Protection Device

Abstract : Military personnel working in high noise environments could be exposed to noise levels up to 150 dB. Daily noise exposure limits are based on both ambient noise levels and the duration of time spent in that noise environment. NAVAIR led ATI in the development of a ship-suitable in-ear dosimeter integrated into a single hearing protector, and co-sponsored an effort executed by AFRL to validate the effective noise dose measured by in-ear dosimetry. This was accomplished by conducting human noise exposure experiments that calculated noise dose from temporary threshold shifts (TTS) in hearing with and without ATI's in-ear dosimeter. Twenty subjects participated in the study. The data describe the subjects' open and occluded (protected with ATI's in-ear dosimeter) TTS response to noise exposure. Results from this study demonstrated that the ATI in-ear dosimeter integrated into a single hearing protective device overestimated the effective noise dose received by subjects by an average of 11 dB.