Velocity differences in laryngeal adduction and abduction gestures

Area of Science:

• Biomechanics
• Speech Science
• Laryngeal Physiology

Background:

• Understanding laryngeal muscle function is crucial for speech production.
• Quantifying the dynamics of vocal fold gestures provides insight into phonation control.

Purpose of the Study:

• To objectively measure and compare the velocities of laryngeal adduction and abduction gestures.
• To investigate the biomechanical and neural factors influencing these vocal fold movements.

Main Methods:

• 16 subjects produced periodic laryngeal adduction and abduction gestures.
• Cuneiform tubercle movements were tracked using laryngoscopic recordings.
• A piecewise linear model analyzed cuneiform tubercle trajectories to determine velocities.

Main Results:

• Abduction velocity was significantly faster than adduction velocity.
• Abduction velocity was up to 51% higher than adduction velocity.
• Adduction velocity may be actively limited to prevent overshoot during phonation initiation.

Conclusions:

• Laryngeal biomechanics and active neural control contribute to differential adduction/abduction velocities.
• Faster abduction may be a passive biomechanical property, while slower adduction could involve active neural modulation.
• These findings enhance our understanding of vocal fold dynamics during speech production.