Onset of auditory deprivation.

The purpose of this investigation was to study further the assertion that auditory function deteriorates in the unaided ear of individuals with sensorineural hearing loss (SNHL) who receive monaural hearing aid fittings. The word recognition scores (WRSs) of 77 monaurally and 65 binaurally fitted subjects with symmetric bilateral SNHL were examined at 1, 3, and 5 years post hearing aid fitting. The deterioration in auditory function was defined as a significant change in the WRSs for Northwestern University Auditory Test No. 6 (NU-6) materials in the unaided ear of individuals fitted with a monaural hearing aid arrangement. Analyses of the data indicate that 25 percent of the monaurally fitted subjects experienced a significant change in the WRSs of their unaided ears, whereas only 6 percent of the binaurally fitted subjects experienced a significant change in the WRSs of either ear. Auditory function does deteriorate in the unaided ears of individuals with SNHL who receive monaural hearing aid fittings. Moreover, the decline in auditory function of the unaided ear does not result from a decrease in hearing sensitivity.