Responses to Intensity-Shifted Auditory Feedback During Running Speech

Area of Science:

• Speech production and perception
• Auditory-motor control
• Prosody and linguistics

Background:

• Prosodic features like stress, pitch (fundamental frequency - F0), intensity, and duration are crucial for conveying linguistic meaning.
• Understanding how these features are controlled during speech production is key to understanding speech motor control.
• Previous research suggested integrated control mechanisms for prosodic features, particularly F0.

Purpose of the Study:

• To investigate whether speech prosodic features, specifically intensity, fundamental frequency (F0), and duration, are controlled independently or in an integrated manner.
• To determine how speakers compensate for auditory intensity perturbations during running speech.

Main Methods:

• Nineteen healthy adults produced sentences with emphatic stress on either the first or second word.
• Participants experienced upward or downward intensity perturbations during stressed word production.
• Compensations were measured by comparing peak F0, peak intensity, and word duration during perturbed versus baseline trials.

Main Results:

• Significant intensity compensations were observed in the downward perturbation group, indicating sensitivity to intensity changes.
• No significant compensations for fundamental frequency (F0) or word duration were found in either perturbation group.
• Results suggest that intensity control during speech may operate independently from F0 and duration control.

Conclusions:

• Speakers demonstrate sensitivity to auditory perturbations affecting their intended speech output.
• Evidence supports an intensity-specific compensation mechanism, contrasting with previous findings for F0.
• Discrepancies may indicate distinct control mechanisms for F0 and intensity, or a threshold-dependent modulation of prosodic control.