Abstract:

Previous studies showed a strong correlation between cervical and vocal fold smears [Abitbol , J. Voice 13, 424–446 (1999)]. Myers [Eur. J. Obstet. Gynecol. Reprod. Biol. 144S, S82–S89 (2009)] found significant changes in mechanical properties of tissues during pregnancy. This suggests that similar changes may occur also in laryngeal tissues, affecting conditions for vocal fold vibration. Recordings of audio, electrolaryngograph, oral pressure, and air flow signals were made of a professional classically trained soprano once per week, starting on week 28 of pregnancy. The tasks comprised reading a text and singing a song. In addition, the singer repeated the syllable [pae] while performing a diminuendo at various pitches, allowing determination of the lowest pressures producing vocal fold vibration and contact, i.e., the phonation and contact threshold pressures [Enflo and Sundberg (unpublished)]. Oral pressure during the occlusion for the consonant [p] was accepted as an estimate of subglottal pressure. Voice source was analyzed by means of inverse filtering and the relation between this pressure and various voice source parameters was analyzed. Preliminary results of this exploratory study show substantial effects of pregnancy on voice production.