Speech Perception in Noise and Cortical Auditory Evoked Potentials in Individuals with Auditory Neuropathy Spectrum Disorders

Balan JR and Jaisinghani P

Published on: 2021-12-30

Abstract

Background and Objectives: The study aimed to investigate the relationship of auditory late latency response (ALLR) with the speech identification scores (SIS) in quiet and in noise (SPIN), in individuals with Auditory Neuropathy Spectrum Disorders (ANSD). Methods: The study incorporated repeated measure research design. Based on the purposive sampling 35 individuals with ANSD were selected. Their speech identification scores were assessed in quiet as well SPIN at 0dB SNR conditions. ALLR was recorded using standard protocol with vertical montage (Cz-M1 and Cz-M2 with the ground electrode at nasion). The peak latency and the amplitude of N1-P2 of ALLR were noted. Result: The group data were categorized based on the 95% confidence interval of speech in noise as well as speech identification scores. The difference in the latency and amplitude of ALLR was compared across two groups. There was no statistically significant difference between the groups. Grouping of participants with ANSD was also done based on the presence and absence of LLR. The SPIN and SIS were also compared between the groups but no statistical significant difference was obtained between the groups. The participants with ALLR present were also categorized into good ALLR groups and the poor ALLR groups based on the 95% confidence interval of amplitude of N1-P2 of the right ear. The results showed that there is no significant difference in the SIS as well as SPIN between the two groups. Pure Tone average, SIS, SPIN and the duration of hearing loss was tried to correlate with the latency and amplitude of LLR in ANSD. The results showed no significant correlation of any of these parameters with their ALLR. Conclusion: ALLR depicts the registration of the stimulus at the cortex and is less dependent on the onset of the stimulus. Therefore, neither the presence of ALLR nor its characteristics when present can be taken as an index or indicator of good speech perception.