Sabol J W, Lee L, Stemple J C
School of Music, Syracuse University, New York, USA.
J Voice. 1995 Mar;9(1):27-36. doi: 10.1016/s0892-1997(05)80220-6.
The purpose of this study was to investigate the effects of isometric-isotonic vocal function exercises, practiced regularly for 4 weeks, on parameters of voice production in the healthy singer. A total of 20 university graduate-level voice majors of similar age and vocal training were divided into experimental and control groups, each containing 3 men and 7 women. Each group continued their regular singing practice regimen and the experimental group added the vocal function exercise program. Assessment included acoustic and aerodynamic measures, videostroboscopic ratings, and subjective evaluations. Experimental subjects demonstrated significant improvements in posttest aerodynamic measures of flow rate, phonation volume, and maximum phonation times, suggesting an increase in glottal efficiency.