Simulation of sensorineural hearing impairment

A hearing loss simulation system (HELOS) was designed and constructed to simulate various aspects of sensorineural hearing impairment. The theoretical bases for HELOS were several threshold and suprathreshold auditory phenomena typically exhibited by people with sensorineural hearing losses. In addition to providing differential attenuation of acoustic signals across the frequency range, HELOS simulated loudness recruitment, loudness discomfort thresholds, reduced dynamic range, and reduced frequency selectivity. Three basic audiometric configurations were chosen to investigate the effects of the aforementioned components of a sensorineural hearing impairment on the auditory perception of speech. They were: (1) a sloping high-frequency hearing loss; (2) a flat, severe hearing loss; (3) a severe/profound hearing loss. The battery of tests administered to a group of normal-hearing adults consisted of pure-tone audiometry and PB-word recognition tests, as well as vowel and consonant identification tests. For comparable audiometric configurations, the results from the speech-perception tests were in good agreement with the published results of similar tests administered to persons with sensorineural hearing losses.