Hearing protection devices (HPDs) are essential safety equipment for workers in noisy settings but can also degrade auditory perception. For example, dozens of studies have demonstrated that HPDs disrupt sound source localization, a critical limitation for some use cases. However, a majority of studies have evaluated performance for a small sample of practiced participants, a small number of source locations, and/or a small set of HPDs, making it difficult to distill generalizable factors affecting performance. This talk will present human localization performance data from a larger study focused on quantifying and predicting impacts of HPDs on auditory perception. Sound localization was measured in 130 participants across two study sites. At each site, test stimuli spanned 24 source locations (eight azimuths, three elevations) in five different listening conditions—open ears and four different HPDs. In all conditions, test stimuli were brief noise bursts. In some conditions, multiple source levels or durations were tested. Observed performance degradations suggest impacts of both HPD-induced spatial cue distortion per se and reduced air-conducted stimulus audibility, i.e., insertion loss. Observations are discussed with respect to previous literature and provisions of ANSI S3.71, including impacts of task and stimulus design, individual variability, and training.
Audet et al. (Wed,) studied this question.