[Alterations of speech audiometry in presbycusis brought about by cochlear acoustic emissions]

Click-evoked oto-acoustic emissions (EOEs) and speech audiometry were recorded in a group of normally hearing subjects (n = 56 ears), and a group of patients demonstrating sensorineural hearing loss due to presbycusis (n = 39 ears). Correlations were made between detection-threshold of EOEs, speech reception threshold (i.e., lowest hearing level at which the subject can repeat 50% of a message), and discrimination score (i.e., discrimination score determined 35 dB above the speech reception threshold). EOEs have never been observed when speech reception threshold was equal to or greater than 35 dB HL. EOEs were always found when speech reception threshold was equal to or lower than 25 dB HL. Moreover, the detection-threshold of EOEs increased when increasing speech reception threshold. On the other side, there was not a good correlation between the discrimination score and the detection-threshold of EOEs. Thus, complementary information on outer hair cell degenerative changes in presbycusis could be deduced from these data.