Meniere’s disease is a disease of membranous inner ear characterized by deafness, vertigo and usually tinnitus and has as its pathologic correlate hydropic disease of the endolymphatic hydrops. There is no test that conclusively establishes the diagnosis of Meniere’s disease. As part of a diagnostic protocol, EcochG (SP/AP ratio) test has been proposed as a viable objective test. Otoacoustic emission (OAEs) originate from very specific location in the cochlea are closely linked to the function of outer hair cells. Thus, the latency and amplitude of Distortion Product Otoacoustic Emission (DPOAEs), afford valuable information about cochlear processes such as study of traveling wave propagation. However, most DPOAE studies deal with amplitude aspect. In this study, investigate the DPOAE latency between normal hearing group and patients with Meniere’s disease group verify it’s statistical significance.
DPOAEs latency for 25 patients (7 male and 18 female) with unilateral Meniere’s disease diagnosed patients were analyzed in this study. The patients ranged in age from 20-66 (mean 37.9 years) In all ears with pure tone threshold better than 30dBHL from 500 Hz to 8 kHz. The result were as follow: SOAEs were present in 17 of the 25 Meniere’s disease ears (68%) among the 17 ears with SOAEs the number of emission per varied from one to five, and they were distributed in the range of 903-6,067 Hz, levels ranged from -22.0 to 0.7 dBSPL. The prevalence of SOAEs in the Meniere’s disease ear tended to be greater than in the normal ear. The latency decreased as frequency increases up to 8 kHz for both in patients with Meniere’s disease and control groups. The mean value of DPOAE latency for normal ears was significant prolonged than that of ears with Meniere’s disease ears in 1 kHz, 2 kHz (p<.05).
There was no gender effect for all frequencies (p>.05). There was no significant relationship between DPOAE latency and presence of SOAEs in patients with Meniere’s disease.
KEY WORDS:DPOAEs·SOAEs·Meniere’s disease.