Reduced efficiency of audiovisual integration for nonnative speech

Area of Science:

• Speech Perception
• Audiovisual Integration
• Second Language Acquisition

Background:

• The impact of visual cues on nonnative speech perception is under-researched.
• Native listeners' understanding of accented speech can be influenced by visual information.

Purpose of the Study:

• To investigate how visual cues affect native English listeners' perception of English spoken by native English and Korean speakers.
• To determine if visual cues improve intelligibility for both native and nonnative accented speech.

Main Methods:

• Compared listener ratings and word intelligibility in audio-only versus audiovisual conditions.
• Examined English sentences produced by native English speakers and Korean speakers with accents.
• Assessed the influence of implicit visual biases on speech perception.

Main Results:

• Korean-accented speech was perceived as more accented in the audiovisual condition compared to audio-only.
• Visual cues improved word intelligibility for native English speech but offered less benefit for Korean-accented speech.
• Lower intelligibility for accented audiovisual speech correlated with listener-related implicit visual biases.

Conclusions:

• Visual cues do not uniformly enhance nonnative speech perception and can sometimes increase perceived foreign accent.
• Implicit listener biases play a role in the effectiveness of audiovisual integration for understanding accented speakers.
• Further research is needed to understand listener-specific factors in nonnative speech processing.