Acoustic and aerodynamic measures of the voice during pregnancy.

BACKGROUND Known influences of sex hormones on the voice would suggest pregnancy hormones could have an effect, yet studies using acoustic measures have not indicated changes. Additionally, no examination of the voice before the third trimester has been reported. Effect of pregnancy on the voice is relatively unexplored yet could be quite relevant to female speakers and singers. OBJECTIVES/HYPOTHESIS It is possible that spectral and aerodynamic measures would be more sensitive to tissue-level changes caused by pregnancy hormones. DESIGN/METHODS In this first longitudinal study of a 32-year-old woman's pregnancy, weekly voice samples were analyzed for acoustic (fundamental frequency, perturbation ratios of shimmer and jitter, Harmonic-to-Noise Ratio, spectral measures, and maximum phonation time) and aerodynamic (average airflow, peak flow, AC/DC ratio, open quotient, and speed quotient) parameters. RESULTS All measures appeared generally stable during weeks 11-39 of pregnancy compared with 21 weeks postpartum. Slight decrease in minimum airflow and open speed quotient may reflect suspected vocal fold tissue changes. CONCLUSIONS It is recommended that future studies monitor and test correlations among hormone levels, visual analyses of vocal fold mucosa, aerodynamic function, and glottal efficiency.