Perceptual adaptation to dysarthric speech is modulated by concurrent phonological processing: A dual task study

Area of Science:

• Cognitive Science
• Auditory Perception
• Speech Processing

Background:

• Listeners can adapt to degraded speech signals, such as noise-vocoded speech, even under divided attention.
• Previous research indicated that adaptation to artificial speech degradation is robust across different types of dual tasks.

Purpose of the Study:

• To investigate whether perceptual adaptation to a naturalistic speech variation, dysarthric speech, occurs under divided attention.
• To examine the role of specific attentional processes (phonological, lexical, visuomotor) in adaptation to dysarthric speech.

Main Methods:

• A replication study using an online between-subject experiment with 192 participants.
• Four conditions were employed: speech-only (control), and dual tasks involving phonological, lexical, or visuomotor processes.
• Participants listened to 40 dysarthric sentences while performing the assigned tasks.

Main Results:

• Initial suppression of adaptation and poorer comprehension were observed in the phonological dual task condition during early trials.
• No significant differences in the rate of adaptation were found across the four conditions over 40 trials.
• Overall speech comprehension was lower in the phonological condition compared to speech-only, lexical, and visuomotor conditions.

Conclusions:

• Perceptual adaptation to dysarthric speech can occur effectively under divided attention.
• Speech adaptation appears to be a largely automatic cognitive process, capable of functioning even under cognitive load.