Scaling of glottal opening

Area of Science:

• Laryngology
• Speech Science
• Bioacoustics

Background:

• Laryngeal control involves vocal fold tension (fundamental frequency) and abduction/adduction (vegetative and phonetic functions).
• Abduction/adduction controls voicing, aspiration, and voice quality, with timing crucial for obstruent aspiration.
• The significance and fine control of abduction/adduction gesture size are less understood.

Purpose of the Study:

• To investigate the extent of voluntary control over glottal aperture size.
• To examine glottal aperture control under varying conditions, with and without feedback.

Main Methods:

• Participants attempted to control the size of their glottal opening.
• Experiments were conducted with and without auditory or visual feedback.

Main Results:

• Voluntary control of glottal aperture size was found to be poor.
• Subjects demonstrated an inability to make fine-graded adjustments to glottal opening size.
• Isolated control of glottal opening is limited, suggesting it's coupled with other functions.

Conclusions:

• Precise voluntary control over glottal aperture size is limited.
• This poor control may be due to the limited need for isolated glottal opening adjustments in daily activities.
• Glottal aperture control is tightly integrated with respiration, swallowing, and speech articulation, with precise timing being more critical than precise aperture size in speech.