Maximizing phonation: impact of inspiratory muscle strengthening on vocal durations and pitch range

Background: This study investigated the acute effects of inspiratory muscle warm-up (IWU) on vocal performance in singers. Proper vocal and respiratory warm-up can enhance vocal range, quality, and endurance. The aim was to determine whether IWU improves maximum phonation time and pitch range, contributing to better voice production efficiency (vocal efficiency) and reduced fatigue. Materials and methods: Singers were selected from the Samsun State Opera and the Ballet Directorate (n = 16). This cross-sectional study aimed to investigate the acute effects. The singers in the control group (SC = 8) performed only one session of routine voice warm-up, and the experimental group (SE = 8) conducted an inspiratory muscle warm-up (IWU) of 2 sets, 30 times/set at 40% maximal inspiratory pressure (MIP) in addition to routine voice warm-up. Subsequently, All participants were then required to perform pre- and post- pulmonary function tests, maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), and voice recordings (note high pitch, note low pitch, high pitch durations and low pitch durations sustained with one breath, and maximum phonation duration). Results: All pulmonary function and muscle strength parameters improved in the SE group, with the highest increases in MIP (22.9%) and MEP (14.7%). No significant improvements were noted in the SC group (p > 0.05). The Borg Rating of Perceived Exertion showed that the SE group experienced less difficulty with their vocal performance after IWU (-11.6%, p = 0.006), while no significant change was observed in the SC group (p = 0.316). Both warm-up methods used in the study significantly affected the frequencies of high-pitch sounds (SE = 17.8%, SC = 10.9%, p = 0.003); however, the frequency of low-pitch sounds was not significantly affected (p = 0.437). IWU significantly affected the high-pitched note duration (p < 0.001; 32.17%), low-pitched note duration (p < 0.001; 27.11%), and maximum phonation time (p < 0.001; 21%), while routine voice warm-up did not significantly affect any parameter (p > 0.05). Conclusions: The combination of IWU with the general body and voice warm-up protocol can acutely improve vocal performance in terms of maximum phonation time, phonation times of the highest and lowest pitched sounds in a single breath, and vocal range levels.