Air Pressure and Contact Quotient Measures During Different Semioccluded Postures in Subjects With Different Voice Conditions

Abstract

The purpose of this study was to investigate the effect of phonation into tubes in air and tubes submerged in water on air pressure variables and vocal fold adduction in subjects with different voice conditions. Forty-five participants representing four vocal conditions were included: (1) subjects diagnosed with normal voice and without voice training, (2) subjects with normal voice with voice training, (3) subjects with muscle tension dysphonia, and (4) subjects with unilateral vocal fold paralysis. Participants phonated into different kinds of tubes (drinking straw, 5 mm in inner diameter; stirring straw, 2.7 mm in inner diameter; silicon tube, 10 mm in inner diameter) with the free end in air and in water. Aerodynamic, acoustic, and electroglottographic signals were captured simultaneously. Mean values of the following variables were considered: glottal contact quotient (CQ) measured by electroglottograph, fundamental frequency, subglottic pressure (Psub), oral pressure (Poral), and transglottal pressure. All exercises had a significant effect on Psub, Poral, transglottal pressure, and CQ (P < 0.05). Phonation into a 55-cm silicon tube submerged 10 cm in water and phonation into a stirring straw resulted in the highest values for CQ, Psub, and Poral compared with baseline (repetition of syllable [pa:]) for all vocal status. Poral and Psub correlated positively. During semioccluded exercises, most variables behaved in a similar way (same trend with a quite large individual variation) regardless of the vocal status of the participants.