Modeling the effects of a posterior glottal opening on vocal fold dynamics with implications for vocal hyperfunction

Area of Science:

• * Acoustics and Biomechanics
• * Voice Production and Pathology

Background:

• * The impact of posterior glottal gaps on vocal fold vibration and sound is not fully understood.
• * These gaps are frequently observed in both normal and pathological voice use.

Purpose of the Study:

• * To numerically investigate the effects of posterior glottal gaps on vocal fold tissue dynamics and acoustics.
• * To model vocal hyperfunction using a computational approach.

Main Methods:

• * Utilized a specialized flow solver and a reduced-order model of human phonation.
• * Simulated posterior gap areas ranging from 0.03-0.1 cm².
• * Modeled vocal hyperfunction by increasing lung air pressure to compensate for vocal loudness loss.

Main Results:

• * Posterior gaps reduced energy transfer from fluid to vocal folds by 42%-80%.
• * Radiated sound pressure level decreased by 6-14 dB with posterior gaps.
• * Simulated vocal hyperfunction showed increased maximum flow declination rate and unsteady flow amplitude.
• * Unsteady flow amplitude correlated linearly with collision forces, indicating vocal hyperfunction.

Conclusions:

• * Posterior glottal gaps significantly alter vocal fold dynamics and acoustics.
• * The study provides a computational model for understanding vocal hyperfunction and its relation to glottal gap parameters.
• * Amplitude of unsteady flow can serve as an indicator of vocal hyperfunction severity.