Performance-intensity functions as a predictor for binaural amplification.
It has been suggested that a generalized central auditory deficit which is often present in the aged population might be a contraindication for successful hearing aid use. The present study examined the relationship between measured central auditory deficit and binaural versus monaural aided performance. Subjects were adults, aged 65 or older, with bilateral sensorineural hearing impairments. Unaided phonetically balanced monosyllabic word (PB) and Synthetic Sentence Identification (SSI) performance-intensity functions were obtained followed by aided monaural and binaural speech recognition measurements. A direct relationship between measured central deficit (PBmax-SSImax) and binaural versus monaural superiority was not found because most subjects showed no significant differences for the PB/SSI or binaural/monaural measurements. The best predictor for binaural superiority was found to be the slope of the performance-intensity function, with significant correlations obtained for both the PB and SSI materials.