Intensity on the Speech Evoked Auditory Late Latency Response

The Effect of Intensity on the Speech Evoked Auditory Late Latency Response in Normal Hearing Individuals

Hari Prakash ¹ ,  

Aju Abraham ¹ ,  

Bellur Rajashekar ¹ ,  

Krishna Yerraguntla ¹  

¹ Department of Speech and Hearing, School of Allied Health Science, Karnataka, India  

J Int Adv Otol 2016; 12: 67-71
DOI: 10.5152/iao.2016.1776

Abstract

OBJECTIVE: Among the stimulus factors, the influence of presentation level is less studied in normal-hearing individuals when using speech stimuli withvarious presentation levels for the auditory late latency response (ALLR). Hence, the present study aimed to explore the Latency-Intensity (L-I) function, i.e., how the latency and amplitude change as a function of intensity using speech stimuli.

MATERIALS and METHODS: Speech-evoked ALLR was obtained from 15 normal-hearing individuals. The syllable/ta/ was used to record ALLR with an intensity of 30, 50, 70, and 90 dBSPL. Electroencephalography (EEG) from five channels was recorded and analyzed offline.

RESULTS: The overall results revealed that there is an influence of intensity on P1 and N1 latencies in a nonlinear fashion. The latency change is consistent at lower intensities than at moderate and high intensities. The amplitude changes did not reach significance, though a decrease with a reduction in intensity was obvious.

CONCLUSION: There is a significant effect of intensity on the latency and amplitude of ALLR in speech stimulus. However, this effect may vary for different speech stimuli.

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