Effects of a Straw Phonation Protocol on Acoustic and Perceptual Measures of an SATB Chorus

Abstract

Recent scholarship has suggested that semi-occluded vocal tract (SOVT) exercises may increase vocal economy of individuals by reducing vocal effort while maintaining or increasing acoustic output. Choral singers, however, may use different resonance techniques or change voicing behaviors in an effort to hear their own sound in relation to others. One investigation revealed significant increases in a choir's mean spectral energy after participating in a straw phonation protocol. However, that study reported only acoustic measures and did not include choristers' perceptions of the choral sound and their own voicing efficiency. The purpose of this study was to measure the effect of a straw phonation protocol on acoustic (long-term average spectrum) and perceptual (self-report) measures of the choral sound of an intact soprano, alto, tenor, and bass (SATB) choir. This is a quasi-experimental, one-group, pretest-posttest design. An SATB choir (N = 48 singers) performed a Renaissance motet, participated in a 4-minute voicing protocol with a small straw, and then sang the motet a second time. They completed the same procedure later in the rehearsal. Long-term average spectrum results indicated no statistically significant mean changes in spectral energy after the SOVT protocols. Most participants, however, perceived that the choir sounded better (78.26%) and that their own vocal production was more efficient or comfortable (73.91%) following the protocol. Choristers perceived less vocal effort while maintaining vocal output after straw phonation, which may feasibly align with extant solo research. More research may determine whether this result is due specifically to SOVTs.