Models of auditory signal processing and perception allow us to generate hypotheses that can be quantitatively tested, which in turn helps us to explain and understand the functioning of the auditory system. Here, the perceptual consequences of hearing impairment in individual listeners were investigated within the framework of the computational auditory signal processing and perception (CASP) model of Jepsen et al. [ J. Acoust. Soc. Am., in press]. Several parameters of the model were modified according to data from psychoacoustic measurements. Parameters associated with the cochlear stage were adjusted to fit the basilar membrane (BM) input/output function estimated from forward masking experiments. The absolute sensitivity of the model was adjusted according to the pure-tone audiogram, and the variance of the internal noise in the model adjusted to predict measured just noticeable differences (JNDs) in intensity discrimination tasks. Simultaneous- and forward-masking experiments with noise maskers were used to test to what extent the model can account for the recovery from forward masking. Notched-noise masking was considered to test the model’s ability to account for individual frequency selectivity. Three groups of listeners were considered: (a) normal hearing listeners; (b) listeners with a mild-to-moderate sensorineural hearing loss; and (c) listeners with a severe sensorineural hearing loss. A fixed set of model parameters were derived for each hearing-impaired listener. The simulations showed that, in most cases, the reduced or absent cochlear compression, associated with outer hair-cell loss, quantitatively accounts for broadened auditory filters, while a combination of reduced compression and reduced inner hair-cell function accounts for decreased sensitivity and slower recovery from forward masking. The model may be useful for the evaluation of hearing-aid algorithms, where a reliable simulation of hearing impairment may reduce the need for time-consuming listening tests during development.
|Publication status||Published - 2008|
|Event||International Hearing Aid Research Conference 2008 - Lake Tahoe, CA, United States|
Duration: 13 Aug 2008 → 17 Aug 2008
|Conference||International Hearing Aid Research Conference 2008|
|City||Lake Tahoe, CA|
|Period||13/08/2008 → 17/08/2008|