Sensory Gating to Speech and Nonspeech Stimulus and Its Relationship to Speech Perception in Noise

Abstract

Purpose: Sensory gating is the cortical phenomenon that involves selective inhibition of responses to task-irrelevant stimuli. Perceiving speech in noise, a situation commonly encountered by humans, requires the irrelevant noise to be inhibited while processing the relevant speech stimulus. We hypothesized that the two (sensory gating and speech perception in noise [SPiN]) might be related and that sensory gating may provide evidence of cortical inhibition involved in SPiN. Method: An observational research following a correlational design was conducted on 10 neurotypical individuals. Auditory sensory gating was assessed using a conditioning–testing paradigm for tone and speech token pairs. The SPiN was measured using standardized sentences in the participants' native language. Results: Differences were observed in the gating index of the P2 peaks of speech and tone pairs. A significant relationship between SPiN and the auditory sensory gating of the P2 peak of the speech-evoked cortical potential was obtained. Conclusion: The results of this preliminary investigation indicate an association between the sensory gating mechanism and neurotypical individuals' ability to perceive speech in noise.

Auditory Sensory Gating: Effects of Noise

“…Four studies have successfully utilized a 170 ms /a/, which has been reported to evoke a successful P50 S2 amplitude suppression [ 40 , 41 , 42 , 43 ]. Therefore, speech stimuli gating paradigms may be applicable in future research evaluating sensory inhibition related to speech processing [ 40 , 41 , 42 , 43 , 44 , 45 ].…”

“…Sensory inhibition, or gating, is measured using CAEPs elicited by identical pairs of sounds such as tones, clicks, and speech. While a click stimulus has been traditionally used, recent studies have reported the implementation of speech sound pairs [ 40 , 41 , 42 , 43 , 44 , 45 ], with several using vowel pairs [ 40 , 41 , 42 , 43 ]. These studies have reported robust gating responses using such stimuli, with the results having a greater real-world application than non-speech sounds.…”

“…A significant relationship has been described between the sensory stage of pre-attentive inhibition and mild SPiN deficits in adults with normal hearing [ 27 , 44 ]. Those with a greater CAEP S1-S2 amplitude difference require a lower SNR to successfully perceive SPiN [ 27 , 44 ].…”

“…A significant relationship has been described between the sensory stage of pre-attentive inhibition and mild SPiN deficits in adults with normal hearing [ 27 , 44 ]. Those with a greater CAEP S1-S2 amplitude difference require a lower SNR to successfully perceive SPiN [ 27 , 44 ]. However, the gating paradigm in these studies was conducted in quiet, leaving the direct effects of noise on the neural encoding of sound during this specific inhibitory stage unknown.…”