Do vocal warm-up exercises alleviate vocal fatigue?

Vocal warm-up (WU) exercises of varying types and durations have been suggested as a way of improving vocal function. However, limited research has been conducted to assess the effects of vocal WU exercises on normal or disordered voices. This study attempted to manipulate vocal function, assessed by phonation threshold pressure (PTP) and self-perceived phonatory effort (PPE) at 3 pitches, in 8 young women who reported symptoms of chronic vocal fatigue. Predictions were that PTP and PPE would decrease after 20 min of vocal WU exercises, increase after 1 hr of loud reading, and decrease after 30 min of vocal silence. Furthermore, greater increases in PTP and PPE were expected when the loud-reading task was preceded by a placebo condition of vocal rest than by vocal WU exercises. Results failed to reveal statistically significant changes in PTP or PPE after any of the experimental tasks. High between-subject variability contributed to this result. Removal of 1 outlier from the sample resulted in a statistically significant difference for PTP across tasks, although post hoc pairwise comparisons failed to detect specific effects. Informal inspection of the data indicated that the most obvious difference was an increase in PTP after the loud-reading task at the highest pitch.