Quantifying Spatial and Temporal Variability of Clear and Loud Speech Produced While Performing a Concurrent...

Area of Science:

• Speech production and motor control
• Acoustic phonetics
• Human-computer interaction

Background:

• Understanding speech variability is crucial for speech synthesis and intelligibility research.
• Attention-demanding tasks can impact motor control, including speech production.
• Higher effort speech styles like clear and loud speech are used to improve intelligibility.

Purpose of the Study:

• To quantify the effect of a concurrent attention-demanding task on speech movement variability.
• To compare variability in habitual, clear, and loud speech styles under dual-task conditions.

Main Methods:

• Analysis of lip and jaw kinematics from repeated utterances.
• Quantification of temporal variability using lip aperture segment duration.
• Quantification of spatial variability using normalized lip aperture amplitude.

Main Results:

• Clear speech exhibited greater temporal and spatial variability than habitual and loud speech.
• Habitual speech showed reduced absolute spatial variability when performing a secondary task.
• Relative spatial variability in habitual speech remained unchanged, suggesting reduced range of motion.

Conclusions:

• Concurrent tasks impact speech movement variability differently across speech styles.
• Clear speech is more susceptible to increased variability under dual-task conditions.
• Findings contribute to understanding the motor control of speech under cognitive load.