Changes in vocal quality as a function of warm-up in trained singers

Vocal warm-up is considered to be an important step for trained singers in preparation for a performance, yet the specific effects of vocal warm-up on subsequent singing are unknown. Some authors have suggested that it has immediate effects on vocal quality (e.g., Browning Henderson, 1991); however, there is no scientific evidence to support this (Sundberg, 1987; Hixon, 1991). The purpose of this investigation was to examine the immediate effects of vocal warm-up on vocal quality in subsequent singing, as measured by vocal perturbation and formant structure. Six singers served as subjects, each with at least one year of vocal training. Each subject participated in three experimental conditions, on three separate days: ( 1) condition A was completed without any vocal warm-up prior to data collection, (2) condition B was completed with data collection subsequent to individualized vocal warm-up, (3) condition C was completed with data collection subsequent to specified vocal warm-up. In each condition, vowel spectra were generated for each subject on three sustained sung productions of /a:/ at a comfortable pitch level and a high pitch level. The data were digitally recorded and then analyzed using C-Speech Software (Version 3. 1 ). Mean values of jitter, shimmer, signalto- noise ratio, formants three and four were derived. Overall mean values calculated from each dependent variable were then compared between the three task conditions by conducting a repeated measures ANOV A, controlling for between-subjects variability. Statistical results of this investigation were nonsignificant. In other words, the directional hypothesis that vocal warm-up significantly affects subsequent vocal quality in singing was not supported by these results. Possible instances of individual effects are discussed, indicating that some subjects revealed probable improved vocal quality with warm-up as measured by vocal perturbation, while others revealed a probable opposite effect with individualized warm-up. Limitations and implications of this study are discussed.