Changes in the peripheral and central auditory performance in the elderly-A cross-sectional study.

Age-related hearing loss (ARHL, formerly presbycusis) is due to a variety of lifetime damages to the auditory system and is characterized by bilateral sensorineural hearing loss, impaired speech understanding in noise and central sound processing deficits. Despite its commonness, the pathogenesis has not been completely clarified yet; especially the existence of an independent central ARHL component still remains controversial. We present the results of a cross-sectional topodiagnostic test battery study which aimed at separating aging- and hearing loss-related effects on all parts of the auditory system by current test procedures. Three groups of 30 participants each underwent extensive topodiagnostic test procedures (otoscopy, tympanometry, questionnaires, pure-tone audiometry, DPOAE threshold measurements, auditory brainstem response, central auditory discrimination tests, and speech-in-noise test). By comparing the results of the normally hearing young (18-26 years) and healthy control group, the normally hearing elderly group (60-80 years) and the hearing-impaired elderly group (60-80 years), we deduced aging and hearing loss-related effects on auditory performance. All measurements indicated a significant deterioration of auditory performance in the elderly, partly associated with aging and partly with age-related hearing loss. Our study thereby contributes to a multifocal concept of ARHL. All parts of the auditory system are impaired by aging, age-related hearing loss, or a combination of both. Further evidence for an independent central ARHL component, not attributable to peripheral hearing loss, is provided by the results of the central auditory discrimination test.