Effects of length and depth of vibration of the vocal folds on the relationship between transglottal pressure and fundamental frequency of phonation in canine larynges.

The relationship between fundamental frequency of phonation (F0) and the change in F0 per unit change of transglottal pressure (dF/dP) was investigated in 3 excised canine larynges. The effects of the length and depth of vocal fold vibration on the relationship between dF/dP and F0 were evaluated. A positive correlation between dF/dP and F0 was observed when an increase in F0 was accompanied by a decrease in the depth of vibration while the length of vibration reached a plateau. Although a negative correlation between dF/dP and F0 was observed in only 1 case, this relationship seemed relevant to the length of vibration. These results help to clarify the adjustments of length and depth of vibration involved in regulating F0.