Effect of Sensorineural Hearing Loss on Speech Evoked Aided Auditory Late Latency Response

Abstract

The aim of present study was to compare the auditory late latency response (ALLR) waveform obtained for naturally produced speech tokens, such as /ba/, /da/, and /ga/ in unaided and aided conditions. It also aimed to evaluate the usefulness of ALLR in selection of amplification device using naturally produced speech tokens. Two groups of participants were taken, including 10 individuals with normal hearing and hearing impairment (9 ears) in the age range of 20 to 50 yrs. Speech evoked ALLR was done both in unaided and aided conditions. Aided ALLR was done with two pre-selected digital hearing aids with first fit. The results revealed that there was significant difference between unaided and aided responses (x2 = 197.04, df = 26, p < 0.001). However, only /ba/ and /ga/ for P1 and /ba/ for N1 showed significant difference at 0.05 significance level. The latency was shorter and amplitude was higher for the group with normal hearing than hearing impaired group. There was difference in terms of latency for the speech sounds taken for the study. /ga/ stimulus was found to have shorter latency and /da/ had longer latency out of three stimuli. Similar pattern was also observed for absolute amplitude. Finding from the present study also revealed that there was significant difference between performances of individuals with sloping sensorineural hearing loss with different hearing aids in aided ALLR. Aided ALLR can help in selection of hearing aids as it mimics the hearing aid processing. It can be suggested to use aided ALLR to select hearing aids as it is objective test and can assessed in shorter duration.