Farklı Maske Gürültülerinin ve Gürültüde Konuşmayı Ayırt Etmenin İşitsel Kortikal N1 Cevabı Üzerindeki Etkisi

Abstract

Difficulty in understanding speech in back ground noise is a commonly reported problem. While changes occur in high-level neural functions in noise, neural responses are weakened with increasing noise. The purpose of this study is to compare the effects of different signal to noise ratios and different maskers on cortical N1 response evoked by sound onsets and sound changes in participants with normal hearing and different speech understanding in noise abilities. Thirty normal‐hearing individuals, with age range from 18 to 30 years (15 males and 15 females) participated in this study. Participants were divided into two groups based on their speech in noise test scores as higher than median value (group-1) and below (group-2). In electrophysiological evaluations, the / ui / stimulus is presented in quiet, +5 dB and +10 dB signal to noise ratio white noise and International Collegium for Rehabilitative Audiology (ICRA) noise. Sound onset and sound change N1 latencies and N1- P2 peak to peak amplitudes were compared between conditions and between groups. While N1 latencies were prolonged in all noise types and signal to noise ratios compared to the quiet condition, the N1- P2 peak-to-peak amplitudes decreased at both signal to noise ratios in ICRA noise compared to quiet. The latencies and amplitudes in ICRA noise compared to white noise at the same signal to noise ratio were prolonged and decreased, respectively. While sound change N1 latencies were higher in ICRA noise +10 dB and white noise +5 dB signal to noise ratio compared to quiet, N1- P2 peak-to-peak amplitudes were lower in ICRA +5, +10 dB and white noise +5 dB signal to noise ratio compared to quiet. No effect of signal to noise ratio on onset and sound change responses was observed. In comparisons between groups; only at white noise +5 signal to noise ratio the onset N1- P2 amplitudes of group-2 were higher than group-1, no correlation was found between speech in noise scores and cortical responses. In conclusion, the presence of noise changes the sound onset and sound change N1 responses, the effect of noise type varies based on the evoked response. Comparison of cortical responses in larger groups with different speech in noise abilities or in people with speech in noise problems may be suggested