Cochlear compression between 500 and 8000 Hz in listeners with moderate sensorineural hearing loss.

Lopez-Poveda, Enrique A. and Plack, Christopher J. and Meddis, Ray and Blanco, Jose L. (2005) Cochlear compression between 500 and 8000 Hz in listeners with moderate sensorineural hearing loss. Hearing Research, 205 (1-2). pp. 172-183. ISSN 0378-5955

Abstract

Psychophysical estimates of basilar membrane (BM) responses suggest that normal-hearing (NH) listeners exhibit constant compression for tones at the characteristic frequency (CF) across the CF range from 250 to 8000 Hz. The frequency region over which compression occurs is broadest for low CFs. This study investigates the extent that these results differ for three hearing-impaired (HI) listeners with sensorineural hearing loss. Temporal masking curves (TMCs) were measured over a wide range of probe (500–8000 Hz) and masker frequencies (0.5–1.2 times the probe frequency). From these, estimated BM response functions were derived and compared with corresponding functions for NH listeners. Compressive responses for tones both at and below CF occur for the three HI ears across the CF range tested. The maximum amount of compression was uncorrelated with absolute threshold. It was close to normal for two of the three HI ears, but was either slightly (at CFs 1000 Hz) or considerably (at CFs 4000 Hz) reduced for the third ear. Results are interpreted in terms of the relative damage to inner and outer hair cells affecting each of the HI ears. Alternative interpretations for the results are also discussed, some of which cast doubts on the assumptions of the TMC-based method and other behavioral methods for estimating human BM compression.