Adults with normal hearing in the normative values ​​of the chirp stimulus

Auditory brainstem response; is a non-invasive and reliable test, which assesses electrophysiological functions till subcortical structures starting from cochlea and does not require participation of patient and used in neurological and audiologic diagnosis. Although ABR is an objective test, it varies according to the wave latencies and amplitudes stimulating type, used parameters as well as age and sex of the individual. Because of these differences, each clinic should establish its normal values, and determine its standards. In this study, it is aimed to determine V wave latencies and amplitudes on normal hearing adults via chirp stimulus and to establish normative data of our clinic. For this purpose, an overall of 62 subjects, who applied to Başkent University Hospital KBB (Otorhinolaryngology) Clinic and did not have any hearing complaints as well as whose autoscopic inspection was normal as well as composed of 31 female and 31 males, was included to the study. Participants are separated into two groups according to their ages as 18-39 and 40-60. Individuals, whose pure audible mean was maximum 14 dB for 18-39 ages, and maximum 20 dB for 20-40 ages as well as immitansmetric evaluation was normal, were included to the study. In our study, I and III wave attainability was evaluated via chirp stimulus, send at 90, 70, 50, 40 and 20 dB intensities, and formed V wave latencies and amplitudes were measured. At 90 dB intensity, I wave could not be obtained for 17 individuals, and III wave could not be obtained for 14 individuals. Maximum amplitude (0,41 µV ± 0,12 µV) on the V wave values, obtained from all individuals, was determined at 70 dB, and the lowest latency (4,62 ms ± 0,34 ms) was determined at 90 dB. During the evaluations, made according to sex, V wave latencies were obtained later on men. During the evaluations, made according to age groups, 40-60 age group V latencies were found later. V wave latencies and amplitudes from our study form the chirp stimulus ABR standards of our clinic. It shall form a reference for the future studies. Keywords: Auditory brainstem response, ABR, Chirp