Effects of Volume, Pitch, and Phonation Type on Oscillation Initiation and Termination Phases Investigated With High-speed Videoendoscopy

Oscillatory Onset and Offset in Young Vocally Healthy Adults Across Various Measurement Methods

“…The VIP 10 was calculated from the total glottal area waveform and is defined as the time in seconds between the 5% and 90% values of the difference between the initial minimum and initial maximum of the polynomial fit (Figure 1). Since the /hi/ task used for this study produces vocal fold oscillations prior to vocal fold closure and the complete adduction, oscillations were considered from the point, which they were first visually identified prior to contact.…”

“…The VOP off as defined by Kunduk et al (2013) 10 was calculated from the glottal area waveform and is defined as beginning when the difference in adjacent glottal minima crossed a threshold of ten pixels (Personal Communication with M. Kunduk on 2/27/15) and ending with the cessation of oscillation (Figure 2). The final 50% of glottal area waveform minima were selected to isolate offset behavior.…”

“…6–9 How the various methods vary in terms of the onset and offset times is one of the questions of this study. This study also investigates the relationship between the oscillatory onset and offset times in large number of vocally healthy adults as limited investigations of oscillatory onset 3,5–7,9–19 and particularly of oscillatory offset 5,9,10 in vocally healthy adults, are on small number of subjects ranging from 1–23 subjects.…”

“…8,14 Similarly, oscillatory offset is broadly characterized by (1) brief duration of non-steady state oscillatory motion, followed by (2) complete cessation of oscillatory motion and vocal fold abduction (75ms or 17±2.5 cycles). 6,10 Clearly, high temporal resolution as offered by high-speed video endoscopy 23,24 and/or videokymography 25 is required to capture these transitory oscillatory segments of the vocal folds during onset 6,12,14 and offset. 6 …”

“…Mergell et al (1998) 7 computed oscillatory onset as the duration of exponential growth from 32.2% to 67.8% of initial to steady-state amplitude derived from the mid-membranous vocal fold trajectories for left and right vocal folds and named this as Phonation Onset Time (POT). Kunduk et al (2006, 2013) 6,10 calculated oscillatory onset as the time period from the first point the frame-by-frame differences in the glottal area waveform reach 5% of the maximum value to the point where the glottal area waveform reaches 90% of its maximum value and named this the Voice Initiation Period (VIP). The above approaches do not take into account the first oscillatory motion of the vocal fold and when the actual steady-state vibrations begin.…”