Effects of Interaural Speech-Recognition Differences on Binaural Advantage for Speech in Noise

The relationship between interaural differences in speech-recognition performance and binaural advantage for speech in noise was studied. Subjects were five hearing-impaired listeners with symmetrical pure-tone air-conduction audiograms and significant interaural differences in speech recognition . All subjects repeated nonsense syllables in the presence of competing noise in monaural and binaural conditions. Binaural advantage was calculated as the difference in signal-to-noise ratio that afforded 50 percent correct performance between the monaural and binaural conditions. The results were diverse. Although the majority of the subjects retained some degree of binaural advantage, a conclusive relationship between interaural differences in speech recognition and binaural advantage could not be established. The implications for binaural hearing aid fittings are discussed.