Bilingual Perception of Dysarthric Speech

Area of Science:

• Linguistics
• Cognitive Science
• Speech-Language Pathology

Background:

• Research on disordered speech perception primarily focuses on monolingual listeners.
• Existing models suggest vocabulary and working memory aid understanding of dysarthric speech in monolinguals.
• It remains unclear if these models apply to bilingual individuals with different cognitive and linguistic profiles.

Purpose of the Study:

• To investigate if bilingualism confers a perceptual advantage in understanding dysarthric speech.
• To determine the roles of working memory and vocabulary knowledge in this potential advantage.
• To examine how different types of bilingualism (early vs. late) influence dysarthric speech perception.

Main Methods:

• Ninety-four participants were categorized as monolinguals, early bilinguals, or late bilinguals.
• Participants completed a speech perception task involving transcribing dysarthric speech.
• Working memory and vocabulary assessments were administered to all participants.

Main Results:

• Early bilinguals showed lower intelligibility scores for dysarthric speech compared to monolinguals and late bilinguals.
• Vocabulary knowledge significantly predicted intelligibility across all groups.
• Working memory did not predict intelligibility scores.
• Earlier English language exposure in early bilinguals correlated with higher intelligibility.

Conclusions:

• Vocabulary knowledge and language experience are more critical than working memory for understanding disordered speech.
• Models of disordered speech perception need to incorporate listener variability, including bilingualism.
• Age of language exposure is a significant factor in the ability to perceive dysarthric speech.