Acoustic Comparison of Lower and Higher Belt Ranges in Professional Broadway Actresses

Current research on the female belt voice has generally been limited to the range of C5, which is not representative of the current requirements on Broadway. Additionally, much belt research uses voice teachers or college students. The goal of this study was to acoustically examine both higher and lower belt ranges in 10 women who have performed belt roles on Broadway during the last decade.

We analyzed the long-term average spectrum of the middle stable portion of three belted pitches, one from a lower, more traditional belt song and two from a higher, more contemporary belt song. The dB levels of the first three peaks in the long-term average spectrum corresponding to the first three harmonics were extracted and compared across tasks. Age, professional roles played on Broadway, and self-perceived belt strategy were obtained via interview to find potential unifying factors in resonance strategies.

Overall, the dB level of the peaks closest to the second and third harmonics were higher than the peak close to the fundamental frequency. The difference between peaks was statistically greater in the lower belt compared to both higher belt tasks, indicating these singers relied more on a single harmonic in the lower belt range than the higher belt range. In the higher belt range, there was less variability between peaks. No patterns emerged between resonance strategies and demographic information.

Elite female belters use varying resonance strategies to create commercially viable belt sounds in different belt ranges.