Pathophysiological and Clinical Aspects of Hearing Loss Among 85-Year-Olds.

Abstract

This study aimed to identify the prevalence of conductive/mixed and sensorineural hearing loss, with an attempt to differentiate between sensory and neural components in 85-year-olds. A comprehensive auditory test protocol, including pure-tone audiometry, speech audiometry, auditory brainstem response (ABR), and distortion product otoacoustic emission (DPOAE), was used to identify different types of hearing loss in 85-year-olds. This study comprised a subsample (n = 125) selected from an unscreened cohort of 85-year-olds born in 1930, within the Gothenburg H70 Birth Cohort Studies in Sweden. Test results were reported descriptively. Sensorineural hearing loss was present in one or both ears in almost all participants (98%), and the majority had absent DPOAEs. Only approximately 6% had additional conductive hearing loss, that is, mixed hearing loss. Approximately 20% of the participants with a pure-tone average at 0.5-4 kHz < 60 dB HL had worse word recognition scores compared with predicted scores by the Speech Intelligibility Index (SII), whereas only two participants were classified with neural dysfunction with the use of ABR. Sensorineural hearing loss, likely related to outer hair cell loss, was present in the vast majority of 85-year-olds. Conductive/mixed hearing loss appears to be relatively rare in advanced age. Poor word recognition scores in relation to SII-predicted scores were relatively common (20%) in 85-year-olds, whereas auditory neuropathy was only rarely identified (1.6%) by the use of ABR latencies. To explain abnormal word recognition and to identify the neural component of hearing loss among the older-old population, future research should consider factors such as listening effort and cognition among the older-old population.