SS07: PSYCHOACOUSTICS, SPEECH PERCEPTION AND AUDITORY SIGNAL PROCESSING

MODELLING SENSORINEURAL HEARING LOSS WITH A NONLINEAR AUDITORY FRONT-END

Torsten Dau

Centre for Applied Hearing Research, Department of Electrical Engineering, Technical University of Denmark, DK-2800 Lyngby,Denmark

Recently, an auditory signal processing model was developed, which could simulate psychoacoustic data from a large variety of conditions related to spectral and temporal masking in normal-hearing listeners (Jepsen et al., 2008). The model includes the dual-resonance non-linear (DRNL) filterbank suggested by Lopez-Poveda and Meddis (2001) to simulate the non-linear cochlear signal processing, and is otherwise similar to the modulation filterbank model by Dau et al. (1997). In the present study, the model parameters were modified to simulate cochlear hearing impairment. The modifications of the model were based on individual data from notched-noise masking and forward masking and were associated with changes of the parameters of the DRNL stage of the model. Data from a pure-tone audiogram were used to further reduce the listeners’ sensitivity in connection with an assumed loss of inner hair cells. In addition, intensity discrimination and modulation-depth discrimination experiments were performed in order to estimate potential retro-cochlear (central) limitations in the processing of supra-threshold stimuli. The model helps understanding the perceptual consequences of hearing impairment in individual listeners and can be useful for the evaluation of hearing-aid processing.

Jepsen, M.L., Ewert, S.D., and Dau, T. (2008). A computational model of auditory signal processing and perception, J. Acoust. Soc. Am.124, 422-438.

Meddis, R., O’Mard, L. P., and Lopez-Poveda, E. A. (2001). A computational algorithm for computing nonlinear auditory frequency selectivity, J. Acoust. Soc. Am. 109, 2852–2861.