Fig. 5.

a Raw sensor output. The program detects the time point P (red line) at which the sensor output reaches the peak during the laryngeal elevation and the zero-cross point is searched backward and forward to identify the start point (the trough T ₁ in b) and end point (the maximum M in b) of laryngeal rising time (LRT). b Integrated sensor signal (gray). The green line P corresponds to the position of the highest peak in a, in which the laryngeal elevation speed becomes maximal. The duration between the trough T ₁ (solid red line) and the peak M (dashed red line) is the duration of LRT. The duration between the time point P and the trough T ₂ is the duration of laryngeal activation duration (LAD)