ABSTRACT
It is well known that listeners with impaired hearing have difficulty under standing speech in noise and localizing sound sources. These difficulties are believed to be due, at least in part, to binaural processing problems. This chapter describes selected results of two studies designed to determine the extent and the basis of these problems and to determine the amplification configuration most appropriate for alleviating these difficulties. The first set of experiments includes unaided measurements of NoS* detection and just noticeable differences in interaural time delay and interaural intensity difference. The second set of experiments includes measurements of binau ral interaction ( N o S n vs. N o S o ) , contralateral interference ( N uS m vs. N mS m) , and virtual localization with and without simulated monaural and binaural amplification. Data are presented for selected subjects from each study, with emphasis on cross-study comparison for listeners who participated in both studies. Overall, results indicate that the effects of hearing impairment on binaural processing and the benefits obtained from binaural amplification vary widely across listeners, even those with similar degree and configuration of hearing loss. It is remarkable that for the listeners participating in both studies, performance measured without amplification is quite similar to performance measured with amplification, particularly binaural amplification.
