Physiological Correlates of Masking Level Difference

Abstract

The present study aimed to check, whether the late latency potentials can be used as a tool to measure electrophysiological masking level difference. If so, what is the relationship between electrophysiological masking level difference and behavioral masking level difference? A total of thirty subjects were taken in the study. Age ranged between 18 and 40 years with a mean age of 24.2 years were included. All of them had hearing thresholds within normal limits. Stimuli for Electrophysiological Masking Level Difference (EMLD) were generated using Matlab R2009a. Both EMLD and Behavioral Masking Level Difference (BMLD) were recorded using bracketing method. ‘P2’ latency for both SoNo and SπNo conditions were compared to check for significant difference. Both EMLD and BMLD values were compared and checked for correlation. Peak latencies of ‘P2’ were significantly different for both SoNo and SπNo condition. Mean values of EMLD and BMLD procedures show no significant difference. There is a significant positive correlation between EMLD and BMLD. MLDs recorded from ALLRs conceded similar magnitude as that obtained from behavioral measures. Since, there was a positive correlation between the EMLD and BMLD, Auditory Evoked Potentials can be used to obtain MLD in difficult to test population to assess functioning of auditory nervous system.