Immersive simulation of hearing loss and auditory prostheses

Abstract

Simulation of hearing loss is useful for demonstrating the communication challenges facing hearing-impaired people. However, current simulations, most of which are only recordings, do not actually elevate thresholds; i.e., they do not simulate hearing loss, per se. The hearing loss simulator described in this talk is immersive; the user’s detection thresh- olds for ambient sounds are shifted by a prescribed degree. This threshold shift is achieved through a combination of passive attenuation (from muff-type hearing protectors) and additive masking noise (introduced by within-muff earphones). Acoustic signals picked up by microphones near each ear are processed through bandpass AGC channels and delivered via the earphones to complete the simulation of frequency-dependent hearing loss and loudness recruitment. Preliminary results validating the accuracy of specified threshold shift will be presented, along with speech-reception data comparing simulated with actual hearing losses. Subjective reactions of users engaged in one-on-one conversation suggest that strong feelings of communication disability are engendered by even moderate degrees of simulated hearing loss. The system, which is capable of simulating any degree of recruiting hearing loss along with hearing aids or cochlear implants, can provide effective interactive demonstrations of both auditory communication handicap and rehabilitation options. [Work supported by NIDCD.]