Auditory Gating in Response to Speech Stimuli

Barr, Jordan

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https://hdl.handle.net/2142/50018 Copy

Description

Title

Auditory Gating in Response to Speech Stimuli

Author(s)

Barr, Jordan

Contributor(s)

Gooler, David M.

Issue Date

2014-04

Keyword(s)

• Speech & Hearing Science
• Auditory Gating
• EEG
• P50
• Stimuli
• Speech

Abstract

Sensory gating is hypothesized to improve perception in a noisy sensory environment and focus attention on novel stimuli. Auditory gating is defined as a reduction in the amplitude of the P50 auditory-evoked potential of the EEG to a test stimulus (S2) in the presence of a preceding, identical conditioning stimulus (S1). S1 and S2 have predominantly been identical acoustic-click stimuli. The assumption is that the reduced P50 amplitude to S2 relative to S1 is a suppression of the response to a redundant stimulus. Few studies have (1) attempted to evaluate stimulus parameters considered to be redundant by presenting S1 and S2 stimuli that differ or (2) used complex sounds such as speech which could presumably contain more meaningful acoustic parameters. This study investigated auditory gating of the P50 evoked potential under conditions where S1 and S2 were identical, and where they were different, consonant-vowel syllables. Healthy, normal-hearing subjects between 18-64 years of age participated in the study. The speech-stimuli were time-compressed, bilabial stop consonant-vowel syllables /ba/ and /pa/ which have different onset and voice-onset times. The S1-S2 pairs were presented with a 500 ms inter-stimulus interval and 8 s between stimulus pairs. S1- S2 stimuli (/ba/-/pa/, /pa/-ba/, /pa/-/pa/, /ba/-/ba/) along with control stimuli (/pa/, /ba/, 3 ms click) were presented in randomized order. For each stimulus condition, evoked responses to 40 presentations were collected in replicate trials that were averaged and analyzed. Auditory gating was present in response to the speech stimuli. Differential effects of stimulus pair combinations will be described.

Type of Resource

image

Language

en

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http://hdl.handle.net/2142/50018

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