A PHYSIOLOGICAL AND ACOUSTIC STUDY ON VOICED BILABIAL FRICATIVE PROLONGED BETA- AS A VOCAL EXERCISE

The voiced bilabial fricative /beta:/ has been used as a vocal exercis e. The present study investigated the effects of the exercise on voice production and voice source. This study compared vowel phonation on t he syllable /a:p/ with the production of the exercise and vowel phonat ion before and immediately after the exercise. The methods were (a) du al-channel electroglottography, from which the vertical laryngeal posi tion was derived, (b) electromyography using surface electrodes, and ( c) inverse filtering of the acoustic signal to obtain an estimate of t he voice source. In the production of /beta:/ as compared with vowel p honation in most of the cases, the vertical laryngeal position seemed to be higher, the muscular activity of the larynx lower, and the slope of the voice source spectrum steeper. In vowel phonation after the ex ercise, the muscular activity seemed to be lower in most cases, althou gh the voice source remained unchanged. This seems to indicate improve d vocal economy.