Voice source characteristics in mongolian "throat singing" studied with high-speed imaging technique, acoustic spectra, and inverse filtering

Mongolian "throat singing" can be performed in different modes. In Mongolia , the bass-type is called Kargyraa. The voice source in bass-type throat si nging was studied in one male singer. The subject alternated between modal voice and the throat singing mode. Vocal fold vibrations were observed with high-speed photography, using a computerized recording system. The spectra l characteristics of the sound signal were analyzed. Kymographic image data were compared to the sound signal and flow inverse filtering data from the same singer were obtained on a separate occasion. It was found that the vo cal folds vibrated at the same frequency throughout both modes of singing. During throat singing the ventricular folds vibrated with complete but shor t closures at half the frequency of the true vocal folds, covering every se cond vocal fold closure. Kymographic data confirmed the findings. The spect rum contained added subharmonics compared to modal voice. In the inverse fi ltered signal the amplitude of every second airflow pulse was considerably lowered. The ventricular folds appeared to modulate the sound by reducing t he glottal flow of every other vocal fold vibratory cycle.