Damping of vocal fold oscillation at voice offset. (August 2017)

• Record Type: Journal Article
• Authors: DeJonckere, P.H.; Lebacq, J.
• Is Part Of: Biomedical signal processing and control. Volume 37(2017)
• Page Start: 92
• Page End: 99
• Publication Date: 2017-08
• Subjects: Damping -- High speed video -- EGG -- Photoglottography -- Flow glottography; Signal processing -- Periodicals; Biomedical engineering -- Periodicals; Signal Processing, Computer-Assisted -- Periodicals; Image Processing, Computer-Assisted -- Periodicals; Biomedical Engineering -- Periodicals; 610.28
• DOI: 10.1016/j.bspc.2016.10.010
• Languages: English
• ISSNs: 1746-8094

Abstract

Highlights: Vocal folds show a damped oscillation while abducting at the end of a vocal emission. This damping reflects important mechanical properties of the vocal oscillator. This damping can be recorded with several glottographic methods, and with high speed film. However intrasubject variability is large, depending on physiological parameters. Further research should focus on a suitable recording protocol. Abstract: Vocal folds show a damped oscillatory movement while abducting at the end of a vocal emission. The phenomenon can be observed with high-speed videoendoscopy and with different glottographic methods. It reflects important mechanical properties of the vocal oscillator, and cannot be voluntarily controlled. It could become a valuable clinical parameter, particularly in a medicolegal context, but its large variability in a same subject limits its use. First, possibilities and limitations of each recording method are reviewed. Second, the three main physiological factors accounting for the variability are analysed: (1) the timing dynamics of the expiratory pressure with respect to the opening of the glottis; (2) the speed at which vocal fold edges are abducted and glottal resistance drops, the combined effect of (1) and (2) determining the persisting transglottal flow, hence a persisting driving force; (3) the morphological change of the oscillator, whose lip-like shape becomes flattened depending on the degree of abduction. For clinical/medicolegal applications, additional research is required as to the recording protocol. A possible solution could be an entire recording with high speed transnasal videokymography of a standardised passage read by the subject, with a posteriori automatic extraction, by dedicated software, of all damping phases and computation of the average damping coefficient.