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Posterior cricoarytenoid as a speech muscle
Summary
The posterior cricoarytenoid muscle (PCA) is crucial for voiceless speech sounds. Our study shows increased PCA activity directly controls vocal fold opening during voiceless consonants.
Area of Science:
- Laryngology
- Speech Science
- Bioacoustics
Background:
- The posterior cricoarytenoid muscle (PCA) is the sole vocal fold abductor.
- Its precise role in speech production remains incompletely understood.
Purpose of the Study:
- To investigate the PCA's function during speech, specifically voiceless consonant production.
- To correlate PCA electromyographic (EMG) activity with glottal opening.
Main Methods:
- Electromyography (EMG) recorded PCA activity in native speakers of American English, Japanese, and Danish.
- Participants produced test words within frame sentences.
- Fiberoptic technique estimated glottal opening, compared with EMG data.
Main Results:
- Consistent increases in PCA activity were observed during the voiceless portions of test words.
- PCA activity levels correlated with the degree of glottal opening.
- Timing of PCA activation influenced the temporal course of glottal opening.
Conclusions:
- PCA activity is directly responsible for regulating glottal aperture during voiceless speech segments.
- Vocal fold abduction by the PCA is key to producing voiceless consonants.
- Adductor muscle suppression also contributes to voiceless sound production.