Effects of the Change in Respiratory Kinematics on the Singing Voice: Re-Visiting the Benefits of Diaphragmatic-Abdominal Breathing in Professional Singers with Problems in Pitch.

To assess the effect of voice therapy on pitch in professional singers with faulty respiratory kinematics. In this prospective interventional study, professional singers with easy voice fatigability and inability to reach higher pitches, following appropriate selection criteria, were subjected to a 1-month structured voice therapy that transformed their predominant breathing pattern from thoracic to diaphragmatic-abdominal. Acoustic parameters (pitch range and its extreme values before/after therapy, and difference in pitch range) were analyzed using Praat software and compared using standard statistical methods (paired -test). The singers' age and career duration were also correlated with the pitch parameters (Pearson's correlation coefficient). The singers (n = 60; 55% men, 45% women; respective mean age: 34.24, 35.92 years; average singing career: 12.56 years) had thoracic breathing before treatment [average pitch-range: 92.8 Hz; 85.84 Hz (men), 101.29 Hz (women)] that turned to abdominal type post-therapy [average pitch-range: 189.21 Hz; 178.54 Hz (men), 202.25 Hz (women)]. The decrease in the mean lowest pitch was significant by paired -test in both men and women ( = 7.96 and 7.87, respectively; .0001 significant level of test), as also the increase in mean highest pitch ( = 23.85 and 17.45, respectively; .0001 significant level of test) and change in pitch range ( = 19.45 and 17.37, respectively; .0001 significant level of test). Correlations between age/career duration with pitch range before and after therapy and its difference varied from very poor to fair [respectively, for men and women, = -.54, = .03 (pre-therapy); = .045, = -.39 (post-therapy); = .21, = -.30; = -.36, = .25 (pre-therapy); = .3, = -.5 (post-therapy); = .29, = -.51]. Voice therapy directed to change respiratory kinematics from thoracic to diaphragmatic-abdominal was significant in the restoration of acoustic voice parameters in professional singers. Their age and duration of singing career had limited roles as adjuncts to voice therapy in the process.