The cricothyroid muscle in voicing control.

Area of Science:

• Linguistics
• Speech Science
• Phonetics
• Physiology

Background:

• Voicing in speech production depends on vocal fold vibration, influenced by adduction, tension, and airflow.
• Manipulating these parameters can control the voiced or voiceless status of speech sounds.
• The cricothyroid (CT) muscle plays a key role in adjusting vocal fold longitudinal tension.

Purpose of the Study:

• To investigate the control of voicing and voicelessness in speech.
• To examine the specific role of changes in vocal fold longitudinal tension, indicated by CT muscle activity.
• To correlate CT muscle activity with consonant voicing and subsequent vowel fundamental frequency (F0).

Main Methods:

• Electromyographic (EMG) recordings of the CT muscle were obtained from speakers of American English and Dutch.
• Linguistic material included reiterant speech with voiced and voiceless consonants (stops, fricatives, affricates) in CV syllables.
• CT muscle activity was compared between voiced and voiceless consonants, and F0 was measured following consonants.

Main Results:

• CT muscle activity was significantly higher for voiceless consonants compared to their voiced cognates.
• A common pattern of higher F0 was observed at the beginning of vowels following voiceless consonants.
• In one case, similar CT activity for voiced and voiceless affricates corresponded to less robust F0 variations.

Conclusions:

• Differences in CT muscle activity suggest active control of vocal fold tension for maintaining or suppressing phonation.
• This mechanism likely underlies the observed differences in voicing and the consonant-induced F0 variations.
• CT muscle activity is a crucial factor in the production of voiced and voiceless consonants and their acoustic consequences.