QUANTITATIVE MEASUREMENT OF MUCOSAL WAVE BY HIGH-SPEED PHOTOGRAPHY INEXCISED LARYNGES

The movement characteristics of mucosal waves of the vocal fold are im portant components in normal phonation. Quantitative studies of the mu cosal wave have used stroboscopic techniques from a supraglottic view, The current study measured displacement of mucosal epithelium during experimental phonation by using high-speed photography from an infragl ottic view. Effects of thyroarytenoid contraction, increased mean airf low rate, and variation of vocal fold length were examined in canine l arynges. Top and bottom vocal fold ''lip'' amplitude, fundamental freq uency, and phase difference were the dependent variables examined. Thy roarytenoid contraction increased the amplitude of the top and bottom lips, decreased the fundamental frequency, and increased the phase di fference. Increase in airflow through the glottis decreased the top li p amplitude and phase difference and appeared to increase the fundamen tal frequency and to decrease the bottom lip amplitude. Vocal fold len gthening decreased the bottom lip amplitude and increased the fundamen tal frequency and appeared to decrease the top lip amplitude and phase difference.