Age-related changes of otoacoustic emission

The aim of the study was to assess age-related changes of the transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) as well as to evaluate age-related changes of DPOAE suppression in adult subjects with normal hearing and presbycusis. Only women participated in the study: 26 young women with normal hearing (20-31 years old) were included into the first group; the second group consisted of 28 elderly (60-74 years old) with normal hearing; the third group included 28 elderly women with presbycusis (mild-to-moderate hearing loss). Age-related decrease of prevalence and amplitude of OAEs was proved to be significant; no significant differences of these data for left and right ears were revealed. Contralateral suppression of DPOAE was noted more often and was the greatest in young listeners and was presented in all frequency range, meanwhile the suppression was minimal and rarely noted in patients with presbycusis. The DPOAE amplitude enhancement in the contralateral noise condition was recorded in all groups of listeners, more often in aged patients both with normal hearing and hearing loss. These results may indicate age-related changes of medial olivocochlear complex, which take place not only in patients with hearing loss but in normal hearing subjects as well.. The findings were confirmed by the results of acoustic reflex measurements obtained in this study.