Progression of sensorineural hearing impairment in aided and unaided ears.

The possibility of "adult onset auditory deprivation" has been proposed as a condition of extensive deterioration of speech discrimination in unaided ears. Pure tone thresholds and speech discrimination were studied in a follow-up examination on 500 patients using hearing aids unilaterally. The follow-up time ranged from 5 to 24 years. In average the same amount of deterioration was obtained in both ears. Deterioration in pure tone thresholds increased after the age of 80 years and speech discrimination after 65 years respectively. The results obtained gave no support to the concept of adult onset auditory deprivation in unaided ears.