Methods and Materials: Investigation of electrically evoked auditory brain stem response (EABR) is a new issue, especially in implanted patients. Experiments were performed in C.I Center of Iranian Institute for Science and research expansion,1996 on 30 implanted patients with 22 spectra and MSP cochlear implant system and 30 normal subjects with the range of 3-33 years.Findings:1- EABR was obtained in the implanted patients.2- Absolute latency of EABR waves is 1-1.5 ms shorter than ABR waves ‘P<0.05).3-Absolute latency of wave V decreases as a function of electric stimulus magnitude (P<0.05).4- No significant difference was observed in IPL Ill-V between ABR and EABR.

Background and Aim: In neural response telemetry (NRT), intracochlear electrodes stimulate the auditory nerve and record the neural responses. The electrical stimulation send to the auditory nerve by an electrode and the resulted response, called electrically evoked compound action potential (ECAP), is recorded by an adjacent electrode. The most important clinical applications of this test are evaluation and monitoring the intra and postoperative responses of auditory nerve and help to primary setting of speech processor. The aim of this study was evaluating of the potential&aposs threshold changes in three monthes after receiving the devise in pediatric cochlear implant recipients.
Materials and Methods: This longitudinal study evaluated the potential&aposs threshold in four given electrodes in four sessions after receiving the device by approximately one months intervals in children implanted in Amir Alam and Hazrat-e-Rasoul hospitals in 2007, July to December.
Results: ECAP mean threshold level of each electrode did not significantly change in differnent sessions, while there was significant difference between apical and basal electrodes&apos responses in every session(p<0.001).
Conclusion: The reliabiliy of the responses result in more certainty of clinician to fit the speech processor for a long time. Better responses in apical electrodes may lead to develope an effective coding strategy.

Background and Aim: Vestibular evoked myogenic potentials (VEMP) originate from the saccule and the inferior vestibular nerve. In this study, the prevalence of VEMP and latency of the p13 and n23 were compared between three groups of individuals, including symptomatic and asymptomatic Meniere's disease cases and normal participants.

Methods: This study was conducted on 42 cases with the mean age of 40.48 years thirty were Meniere's disease patients, of which 19 were symptomatic and 11 were asymptomatic twelve were normal participants. The VEMP were recorded with 500 Hz tone bursts at 120 dBpeSPL. Then the prevalence and latency of the waves were analyzed and compared in the three above mentioned groups.

Results: The prevalence of VEMP in symptomatic Meniere's disease patients (52.6%) was significantly less than asymptomatic individuals (90.9%) and also normal subjects (100%)(p<0.05). There was no significant difference between latencies of the waves in these three groups (p>0.05). The latency of p13 for symptomatic, asymptomatic and normal participants was 16.41, 15.20 and 14.14 ms, respectively and the latency of n23 for these groups was 20.25, 18.77 and 18.50 ms, respectively.

Conclusion: In Meniere's disease, after medical management, the succule probably regains normal function resulting in re-existence of VEMP. It seems that there is no change in the latency of the waves, most likely due to involvement of the inner ear and intactness of the nerve. VEMP may be a useful test for diagnosis of Meniere's disease and additionally for monitoring the trend of medical management.