Phonation threshold power in ex vivo laryngeal models

Area of Science:

• Laryngeal biomechanics
• Acoustic analysis
• Voice production

Background:

• Phonation threshold pressure and flow are established metrics for voice production.
• Understanding the energy dynamics of phonation is crucial for diagnosing laryngeal abnormalities.
• Phonation threshold power (PTP) integrates airflow and vocal fold tissue properties.

Purpose of the Study:

• To test the hypothesis that phonation threshold power is measurable and sensitive to biomechanical changes in the vocal folds.
• To investigate PTP's responsiveness to variations in posterior glottal gap, vocal fold elongation, and vocal fold lesions.
• To explore PTP's potential as a screening parameter for laryngeal health.

Main Methods:

• Excised canine larynges (n=10 per group) were used to simulate vocal fold conditions.
• Phonation threshold power was measured under varying posterior glottal gaps (0-4mm).
• PTP was assessed with different degrees of bilateral vocal fold elongation (0-20%) and with induced unilateral/bilateral lesions.

Main Results:

• Phonation threshold power showed significant sensitivity to posterior glottal gap (R2=0.298, P<0.001).
• PTP demonstrated weak but significant sensitivity to vocal fold elongation (R2=0.052, P=0.003).
• Phonation threshold power was highly sensitive to the presence of vocal fold lesions (P<0.001).

Conclusions:

• Phonation threshold power is a measurable parameter sensitive to key biomechanical alterations in the larynx.
• PTP's ability to reflect airflow-tissue energy transfer suggests it may be a more comprehensive indicator than PTP or PFF alone.
• PTP holds promise as a broad screening tool for detecting abnormalities in laryngeal function.