Modeling hearing loss as an additional source of masking

This chapter illustrates key elements of typical elevated masked thresholds in hearing-impaired listeners using sets of data from the literature that include masked thresholds for listeners with normal hearing and those with sensorineural hearing loss for identical maskers as well as corresponding quiet thresholds. When presented with a masker at a fixed sound pressure level, listeners with sensorineural hearing loss often have elevated masked thresholds compared to listeners with normal hearing. It is possible to account for this effect by assuming that the hearing loss itself reflects an additional source of masking that combines with the effect of a single external masker in the same nonlinear way that the effects of two external maskers combine. Power-law models of additivity of masking provide a simple description of these complex relationships and a useful framework for development of more detailed models.