Case studies in binaural interference: converging evidence from behavioral and electrophysiologic measures.

We present four case reports of elderly hearing-impaired persons demonstrating a binaural interference effect. Performance measures were poorer when stimulation was binaural than when it was monaural. In the first case the effect is shown for aided speech recognition scores. In the second case it is shown in topographic brain maps of the middle-latency auditory evoked potential. In the third and fourth cases it is shown for both aided speech recognition and the middle-latency response. The effect may be analogous to the phenomenon of binocular rivalry in the visual domain.