A new clinical measure of external laryngeal size which predicts the fundamental frequency of the larynx.

A method for accurately predicting the average fundamental frequency of the larynx from an external measurement of laryngeal size has been developed. In 21 human cadaveric dissections we have demonstrated that the external height of the larynx (measured from the lower border of the cricoid cartilage to the upper border of the thyroid notch) was significantly correlated to the length of the membranous vocal fold (r = 0.94, p less than 0.001). This same external measure of laryngeal size in 115 healthy volunteers was found to be related to their voice fundamental frequency. Significant differences were found between males and females with respect to both laryngeal size (p less than 0.001) and voice fundamental frequency (p less than 0.001). A strong correlation between the external laryngeal measurement and speaking fundamental frequency was found with an overall correlation coefficient for both sexes of 0.8 (p less than 0.001). Using this external measurement, it may be possible to accurately predict the fundamental frequency in males and females. It is proposed that such a measurement could be used to identify various laryngeal diseases and also serve as a basis for corrective treatment in various voice disorders.