Intrinsic velocity differences between larynx raising and larynx lowering

Area of Science:

• Phonetics
• Biomechanics
• Speech Science

Background:

• Vowel production involves distinct larynx positions, with rounded vowels typically requiring a lower larynx than unrounded vowels.
• Pitch variations can further modulate vertical larynx positioning during speech.
• Understanding larynx movement dynamics is crucial for speech synthesis and understanding neural control.

Purpose of the Study:

• To quantify the velocity differences between larynx lowering and raising during cyclic vowel transitions.
• To investigate potential sex differences in larynx movement dynamics.
• To explore the biomechanical and neural underpinnings of observed larynx movement patterns.

Main Methods:

• 23 subjects produced /o-i/ vowel alternations at controlled speaking rates.
• Laryngeal ultrasound imaging with object tracking was used to measure vertical larynx movements.
• Data analysis focused on the velocity of larynx lowering versus raising.

Main Results:

• Larynx lowering was, on average, 26% faster than larynx raising across subjects.
• This velocity asymmetry was more pronounced in female speakers compared to male speakers.
• The findings suggest distinct biomechanical properties influencing larynx movement during speech.

Conclusions:

• The observed asymmetry in larynx movement velocity may reflect underlying neural control strategies and aerodynamic factors.
• These results contribute to a better understanding of articulatory speech movements and their biomechanics.
• Improved models of vertical larynx dynamics can enhance articulatory speech synthesis accuracy.