Examination of cochlear microphonics recorded with different stimulus types according to age, gender and noise sensitivity

Electrocochleography (ECochG), one of the first defined test under auditory evoked potentials, is a total electrical response of inner and outer haircells inside the cochlea and auditory nerve record technique against the presence of an acoustic stimulus. These records should be used in Menier disease and auditory neuropathy spectrum disorder diagnosis, intraoperative monitorization. In addition, cochlear microphonics has a crucial role especially at auditory neuropathy spectrum disorder diagnosis. In our study, healthy individuals were tested with extratimpanic electrocochleography record method via Click and LS CE-Chirp stimulus and the results were compared to the age, sex and noise sensitivity categories. This study has executed at Başkent University Health Sciences Faculty Audilogy laboratory. Study group was consist of 42 volunteers in between 18-40 years old. To understand the suitability of volunteers puretone audiometry, timpanometry and transient otoacoutic emisson tests are performed. Individuals with no hearing loss are tested with 100 dBnHL intensity level via Click and LS CE-Chirp stimulus. The obtained values were statistically evaluated in the SPSS 23.0 program in accordance with the distribution of the data. Independent sample t-test was used for data showing normal distribution, and Mann-Whitney U test was used for data not showing normal distribution. A P<0.05 level was considered statistically significant for all analyzes performed. Cochlear microphonic amplitudes recorded with click and LS CE-Chirp stimuli were recorded to be higher in males than females (p=0.051 and p=0.001, respectively). When the age groups were evaluated, no difference was observed in the CM amplitudes obtained with both click and LS CE-Chirp stimuli. There was no correlation between age and CM amplitudes. In addition, it was determined that the CM amplitudes recorded with the click stimulus in individuals with noise sensitivity were higher than those without noise sensitivity (p=0.051). We think that the obtained data will help the diagnosis in the evaluation of ECochG amplitudes used in the diagnosis of diseases such as auditory neuropathy spectrum disorder.