Laryngeal and Vocal Tract Strategies to Reduce Vocal Fold Contact Pressure

Phonotraumatic vocal hyperfunction is one of the most frequently occurring conditions to affect the voice. This voice disorder often involves vocal fold injury due to repeated, excessive contact pressure between the vocal folds when they collide during voice production. In the clinic, voice therapy attempts to modify unhealthy vocal behaviors through different techniques or exercises. While voice therapy is generally considered effective, the scientific rationale for its therapeutic benefits still remains unclear. It is generally believed that these exercises lead to adjustments in the larynx and vocal tract that reduce vocal fold contact pressure. However, this assumption has never been tested in humans or laboratory experiments. The goal of this clinical trial is to investigate the effectiveness of voice therapy in reducing vocal fold contact pressures and in eliciting the hypothesized favorable laryngeal and vocal tract configurations.

This study will investigate the degree to which a well-documented voice therapy technique, resonant voice therapy, reduces vocal fold contact pressure compared to baseline, and which if any laryngeal and vocal tract adjustments occur in association with this phonation pattern. The investigators will measure contact pressure in vivo in human subjects, and will use computed tomography scans to assess laryngeal and vocal tract configurations before and after initial voice training, in adults with phonotraumatic lesions. The investigators will correlate these measures to patient-reported outcome measures and other secondary outcome measures across longer-term therapy. It is hypothesized that findings regarding favorable physical adjustments associated with reduction in contact pressure shown in this aim will match those identified in our recent simulation studies, and that initial reduction in contact pressure in resonant voice, associated with relevant perceptual, acoustic, and subglottic pressure changes, will correlate with improved long-term voice therapy outcome.

Patients will be those who have been diagnosed by a fellowship trained laryngologist with bilateral mid-membranous lesions that by appearance and history are phonotraumatic and who are referred to resonant voice therapy (RVT). Each subject will receive resonant voice therapy, a standard of care procedure for treating phonotraumatic vocal hyperfunction. The full standardized voice therapy program will have a duration of four weeks, each week with one 60-minute therapy session. All voice therapy sessions will be video recorded. Ten percent of recordings will be randomly selected and used in fidelity checks. Data collection will take place at 3 time points: before therapy (baseline), immediately after an initial therapy session, and after 4 weeks of therapy. At baseline, each subject will fill out a Voice Handicap Index-10 (VHI-10) questionnaire, and will receive videoendoscopic examination, CT scans of the head and neck region during phonation, acoustic and subglottal pressure measurement, and contact pressure measurement. Data collection will be repeated the same day following an initial session of RVT training. Same-day data collection will ensure that lesion characteristics have not changed from baseline, and avoid confounding effects of lesion change in contact pressure measures. Degree of resonant voice acquisition will be determined by speech language pathologists (SLPs) real-time and will be further characterized quantitatively by post hoc perceptual evaluation and acoustic measures. Finally, after 4 weeks of RVT, follow-up measure will include VHI-10, endoscopic exam, perceptual, acoustic, and subglottal pressure measurement.