Do body mass index and fat volume influence vocal quality, phonatory range, and aerodynamics in females?

PURPOSE To analyze the impact of body weight and body fat volume on selected parameters of vocal quality, phonatory range, and aerodynamics in females. METHODS Based on measurements of body mass index in combination with body fat volume, 29 normophonic female subjects were classified as normal weight, underweight, and obese. Voice quality was investigated via auditory-perceptual ratings of breathiness, roughness, and overall dysphonia severity, via various acoustic measures and a multiparametric index. Phonatory range performance was examined using selected measures of the voice range profile and speech range profile. Measures of vocally relevant aerodynamics included vital capacity (i.e., VC), expected VC, phonation quotient, and maximum phonation time (i.e., MPT). RESULTS Significant differences between the three weight groups were found across several measures of intensity, VC, MPT, and shimmer. As compared to the other groups, significantly higher values of maximum and minimum intensity levels, as well as sound pressure level during habitual running speech were observed for the obese group (all p-values<0.05); whereas, the underweight group had significantly lower values for VC and ratio of expected to measured VC (p-values<0.01). Furthermore, underweight subjects differed significantly as compared to normal weight subjects with lower MPT (p=0.025) and higher lowest-F0 (p=0.035). Finally the obese group showed significantly lower shimmer values than the normal weight subjects (p<0.05). CONCLUSION Body weight and body fat volume appear to influence select objective measures of voice quality, vocal aerodynamics, and phonatory range performance.