Hearing protection devices (HPDs) are essential safety equipment for workers in noisy settings but can also degrade perceptually important sound features. Dozens of studies have demonstrated that HPDs disrupt sound source localization, and some have sought to link changes in performance with acoustic impacts of HPDs. Prior work by our group quantified such impacts for a limited set of HPDs referenced to behavioral performance with only a small number of human subjects, making it difficult to distill generalizable factors impacting performance. This talk will present electroacoustic HPD localization measures from a larger project focused on quantifying and predicting impacts of HPDs on auditory perception. A summary acoustic metric was developed based on both unoccluded and occluded head-related transfer functions measured using an ANSI-compliant test fixture (manikin) in a hemi-anechoic chamber. The metric assumes that HPDs may disrupt localization via at least three means: (1) attenuation can render air-conducted localization cues inaudible, (2) frequency distortion can disrupt audible monaural localization cues, and (3) asymmetric attenuation can disrupt audible binaural localization cues. The metric was strongly correlated with behavioral performance across six different HPDs in a large sample of human listeners. However, data also evinced variability not readily captured using conventional acoustic measures.
Argo et al. (Wed,) studied this question.