Introduction

This part introduction presents an overview of the key concepts discussed in the subsequent chapters. The part deals with the adequacy of noise as a means of elevating thresholds in listeners with normal hearing without producing additional unwanted alterations in performance on auditory tasks. It suggests that the simulation of hearing loss with a continuous noise in measurements that also include a time-varying masker may result in interactions that are ancillary to the desired threshold elevation. The part argues that additivity of nonsimultaneous masking in hearing-impaired listeners can be accounted for simply by reducing the degree of the compressive nonlinearity found in earlier models of masking additivity. The part explores both the suitability of treating the sensitivity loss of hearing-impaired listeners as a masker, and the manner in which multiple maskers combine to produce greater-than-expected threshold elevations using single and multiple maskers.