Auditory-Motor Interaction for Vocal Rhythms and Resonance in Individuals With Normal and Pathological Voices

Area of Science:

• Speech and Hearing Sciences
• Neuroscience
• Acoustics

Background:

• Auditory-motor integration is crucial for precise voice control.
• Understanding vocal adjustments under different auditory conditions is vital for diagnosing and treating voice disorders.

Purpose of the Study:

• To investigate spontaneous voice and resonance adjustments in individuals with normal and pathological voices under varying auditory conditions.
• To examine how auditory feedback influences vocal motor patterns in healthy individuals, those with vocal fold nodules (VFN), and muscle tension dysphonia (MTD).

Main Methods:

• Accelerometry was used to measure voice and nasal surface vibrations in 23 VFN, 10 MTD, and 18 healthy participants.
• Participants produced sustained vowels under natural hearing, 90-dBC noise, and 60-dBC noise.
• Acoustic parameters (F0, jitter, shimmer, intensity) and nasal accelerometric signals were analyzed.

Main Results:

• Increased vocal intensity was observed in all groups under 90-dBC noise.
• Healthy and MTD groups showed disrupted auditory feedback (increased low-frequency F0 modulations) under 90-dBC noise.
• VFN group showed altered low-frequency F0 modulations under 60-dBC noise and greater mean accelerometric amplitude.

Conclusions:

• Auditory feedback significantly influences vocal fundamental frequency (F0) rhythms and nasal-oral balance.
• Individuals with MTD and VFN may exhibit atypical auditory-motor integration.
• Low-intensity auditory stimulation may promote vocal stability and efficiency.