Physiological Basis of Polyphonic Overtones in Hoomei-False Vocal Folds or Vocal Tract Resonance?

OBJECTIVES

This study aimed to investigate the vocal principles of Hoomei singing.

METHODS

Inner Mongolian Hoomei singers in China were asked to sing 18 types of Hoomei and compare them with the normal pronunciation of /i:/. Spectral analysis was performed using the Short Time Fourier Transform, and laryngoscopy was utilized to observe the changes in pharyngeal and laryngeal cavity movement during different Hoomei singing styles.

RESULTS

We first summarized the characteristics of pharyngeal and laryngeal motion during different Hoomei singing styles by using the endoscopic study to observe changes in the pyriform fossa and the posterior vocal tract cavity. In addition, our study revealed that the dual vibration sound sources formed by the false vocal folds in contact with each other may be crucial for forming polyphonic overtones in some Hoomei. Second, we analyzed a particular type of Hoomei singing and confirmed for the first time the importance of the narrowing of the posterior vocal tract cavity on the formation of Hoomei polyphonic overtones from the opposite side.

CONCLUSION

Both the dual vibration sound sources formed by the false vocal folds touching each other and the resonance formed by the narrowing of the posterior vocal tract cavity is important for forming polyphonic overtones in the Hoomei.