Effects of a straw phonation protocol on acoustic and perceptual measures of choirs

Abstract

Voice instructors, choral directors, and voice professionals have long utilized semi-occluded vocal tract (SOVT) exercises to evoke efficient voicing from their students or clients. These exercises, which involve narrowing and/or lengthening the vocal tract as a means of increasing pharyngeal pressure, can include nasal consonants, lip or tongue trills, raspberries, or vocalizing through a tube or straw. Researchers have noted that the increased pressure reduces the amount of breath pressure required to initiate voicing (i.e., phonation threshold pressure) while maintaining or increasing acoustic output (e.g., sound pressure level, formant intensity). The result may be increased “vocal economy” or “vocal efficiency” (i.e., increased vocal output with decreased effort). Until recently, however, this research was limited to effects on individuals. This paper includes a series of studies in which choirs of varied voicing (SATB, SSAA, and TTBB) sang unaccompanied pieces prior to and after performing voicing exercises through a small stirring straw. Long-term average spectra have indicated that most choirs maintained or increased acoustic output in the conglomerate, choral sound after the protocols. Singers have also perceived improved choral sound and decreased singing effort. These results may interest choral directors who wish to improve the vocal economy of their ensembles.