Article Type

Original Study


Objective We aimed to study the effect of background noise on speech auditory evoked responses in both normal-hearing (NH) individuals and those with sensorineural hearing loss (SNHL) and correlate these neurophysiological results with subjective measures. Background Understanding speech in noisy situations is one of the most complex activities encountered in everyday life. It is dependent on cognitive factors and sound processing at peripheral, subcortical, and cortical levels. These make perception of speech in noise one of the most complex aspects of human communication. Patients and methods Fifty NH individuals and 40 individuals with mild-to-moderate SNHL were subjected to the Speech, Spatial, and Qualities of Hearing Scale questionnaire, the speech perception in noise test, speech auditory brainstem response, and cortical auditory evoked responses using speech syllable/da/in quiet condition and at three different signal-to-noise ratios (SNRs) (+10, 0, and − 10). Results Speech auditory brainstem response results in NH participants showed delayed latencies of both transients (waves V, A, C, and O) and frequency-following response with reduction in amplitudes of onset (V and A) and F wave only in noisy relative to quiet condition, whereas in SNHL delayed latencies and decreased amplitudes of both transients and fractional flow reserve (FFR) were observed. The effect of noise can be seen in all waves of cortical auditory evoked responses – that is, with decreasing SNR response, latency increased and response amplitude decreased in both SNHL and NH. Conclusion Background noise affects both transients and sustained components of speech in NH and SNHL. P1, N1, P2, and N2 components are all affected by SNR, despite their distinct neural generators; this raises the possibility that the effects demonstrated here are reflective of subcortical processing that is propagated to higher levels of the auditory system. cocktail party, speech auditory brainstem response, speech-in-noise perception