title: A long-term observation of spontaneous oto-acoustic emissions (SOAEs).
abstract: In a follow-up study of 22 ears made after a mean interval of 68 months, spontaneous oto-acoustic emissions (SOAEs) showed marked changes. At follow-up visits, fewer SOAEs were recorded than at the first examination. As the set-up employed at follow-ups was much more sensitive, this observation gains even more weight, because--given identical cochlear structures--a greater number of SOAEs ought to have been recorded. In analogy to age-related high-frequency hearing loss, SOAEs recorded at the follow-up examination were found at lower frequencies. This was associated with yet another phenomenon: Precise frequency data (derived from a 4,000 line spectrum) available for 13 SOAEs (7 subjects) from the first examination showed that SOAE frequencies had dropped slightly in all subjects. In 5 of them the frequency drop was significant (p less than 1/1000 in each case).
authors.affiliation: 2nd Department of Otorhinolaryngology, University of Vienna, Austria.
authors.forename: W
authors.initials: W
authors.lastname: Köhler
authors.forename: W
authors.initials: W
authors.lastname: Fritze
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000375:Aging / Q000502:physiology*; D001307:Auditory Perception; D003051:Cochlea / Q000294:innervation / Q000502:physiology*; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged