Fig 1.
Vocal folds of a child without vocal fold nodules (A) and with bilateral vocal fold nodules (B).
The x and y axis are in pixels.
Fig 2.
Illustration of critical points on displacement waveforms.
Time-axis shows normalized glottal cycles and annotations show notation for denoted key events in the cycle, nm = start opening phase, npm = peak displacement, ncm = start of closed phase.
Table 1.
Shapiro-Wilk test of normality for the mean values of the kinematic features.
Table 2.
Shapiro-Wilk test of normality for the standard deviation (SD) values of the kinematic features.
Table 3.
Comparison across mean values of the kinematic features between children with and without nodules.
Fig 3.
Right and left vocal fold displacement waveforms normalized by glottal length (GL) and cycle period for a (a) child with nodules and (b) without nodules.
Darker line denotes the displacement of the left vocal fold. The thin line is the displacement of the right vocal fold.
Fig 4.
Normalized instantaneous velocities derived from the displacement waveforms in Fig 3 for (a) child with nodules and (b) without nodules.
The darker line represents the normalized instantaneous velocity derived from the left vocal fold displacement. The thin line represents the normalized instantaneous velocity derived from the right vocal fold displacement. The y-axis is denoted by glottal length (GL) per cycle.
Table 4.
Comparison across standard deviation of the kinematic features between children with and without nodules.