Investigation of mismatch negativity results using multi feature paradigm of individuals with subjective tinnitus

The mismatch negativity (MMN) test evaluates neural responses to unexpected sounds, is accepted as an objective tool for the evaluation of the neural plasticity in the auditory system. Previosuly, it was suggested that tinnitus may occur due to differences in neural plasticity in the hearing system. The aim of this study is to compare MMN responses of normal hearing individuals with and without tinnitus. Tinnitus Handicap Inventory (THI) was used to evaluate tinnitus-derived annoyance. Sixteen subjects with chronic subjective idiopathic tinnitus and twenty matched healthy controls were included in the study. Multi-feature MMN paradigm was recorded from 22 surface scalp electrodes. The MMN responses of five different deviants, consisting of frequency, intensity, duration, location and silent gap, were compared between the two groups. On the other hand, the amplitudes of MMN responses were statistically different between the groups for all type of the deviants, there was no difference between the groups when MMN latencies were concerned. According to our results, MMN test might indicate a possible impairment in pre-attentive and automatic central auditory processing for individuals with chronic tinnitus and can be used for the evaluation of the habituation in central auditory pathways in individuals with tinnitus. Key Words: Mismatch Negativity, Multifeature Paradigm, Event Realated Potentials, Tinnitus, Central Auditory Processing