The use of auditory models for the prediction of protected-ear localization

Abstract

Several authors have shown that listeners’ natural auditory localization performance is degraded significantly when wearing a hearing protection device (HPD) (Atherley and Noble, 1970; Abel and Armstrong, 1993; Bolia et al., 2001; Brungart et al., 2007; Hobbs et al.,2008). Research suggests that this degradation in protected-ear localization caused by the disruption of the natural spatial hearing cues by physical obstructions such as a plug or muff, as well as active systems’ artifacts like a limited frequency response, temporal processing delay, or artificial directionality. The current work investigated the utility of using existing auditory localization models from The Auditory Modelling Toolbox (Sondergaard and Majdak (2013)), along with measurements of the device directional transfer function, to accurately predict behavioral protected-ear localization performance. Ten listeners were asked to localize 250-ms broadband noise bursts originating from 245 spatial locations surrounding the listener while wearing each of 11 different HPDs (a mixture of active and passive, plugs and muffs). Directional transfer functions were also collected for each subject, device, and location. Results indicate good agreement between observed behavioral results and model predictions when viewed macroscopically (global mean error values), but less agreement was seen on a trial-by-trial basis.