Flow Dynamics and Acoustics from Glottal Vibrations at Different Frequencies

Glottal vibration is fundamental to breathing-related disorders and respiratory sound generation. However, responses of the flow acoustics glottal vibrations different frequencies are unclear. The objective this study numerically evaluate influences on inspiratory airflow dynamics flow-induced signals; from normal phonation that driven by controlled expiratory flows. A computational model was developed comprised an image-based mouth–throat–lung a dynamic glottis expanding/contracting following sinusoidal waveform. Large Eddy simulations were used solve temporal spatial evolutions, pressure signals analyzed using transform algorithms (wavelet, Hilbert, Fourier, etc.). Results show significantly altered flows in trachea, especially at high frequencies. With increasing frequencies, vortices decreased scale moved main walls. Phase shifts occurred between motion rates for all considered. Due phase shift, forces resisted first half contraction/expansion assisted second contraction/expansion. magnitude fluctuation approximately linear with frequency (~f0), while force increased nonlinearly (~f01.85). Instantaneous irregular low (10 20 Hz) but became more regular profile, periodicity, wavelet-transformed parameters. acoustic characteristics specific explored domains, which may be individually or as combination diagnosing vocal fold dysfunction, snoring, sleep apnea, other diseases.