Simulated Laryngeal High-Speed Videos for the Study of Normal and Dysphonic Vocal Fold Vibration

Abstract

Purpose: Laryngeal high-speed videoendoscopy (LHSV) has been recognized as a highly valuable modality for the scientific investigations of vocal fold (VF) vibrations. In contrast to stroboscopic imaging, LHSV enables visualizing aperiodic VF vibrations. However, the technique is less well established in the clinical care of disordered voices, partly because the properties of aperiodic vibration patterns are not yet described comprehensively. To address this, a computer model for simulation of VF vibration patterns observed in a variety of different phonation types is proposed. Method: A previously published kinematic model of mucosal wave phenomena is generalized to be capable of left–right asymmetry and to simulate endoscopic videos instead of only kymograms of VF vibrations at single sagittal positions. The most influential control parameters are the glottal halfwidths, the oscillation frequencies, the amplitudes, and the phase delays. Results: The presented videos demonstrate zipper-like vibration, pressed voice, voice onset, constant and time-varying left–right and anterior–posterior phase differences, as well as left–right frequency differences of the VF vibration. Video frames, videokymograms, phonovibrograms, glottal area waveforms, and waveforms of VF contact area relating to electroglottograms are shown, as well as selected kinematic parameters. Conclusion: The presented videos demonstrate the ability to produce vibration patterns that are similar to those typically seen in endoscopic videos obtained from vocally healthy and dysphonic speakers. Supplemental Material: https://doi.org/10.23641/asha.20151833