Several types of SOVTE have been used and described in both voice rehabilitation and voice training.

The water resistance therapy (WRT) method (a type of SOVTE) consists of phonating different phonatory tasks into a glass tube, keeping the distal end of the tube submerged in water. Research on WRT has suggested the presence of a massage-like effect on vocal folds and vocal tract tissues, and changes in aerodynamic measures, electroglottographic (EGG) contact quotient (CQ), and vocal tract configuration.

These effects are assumed to contribute to vocal economy. Poral modulation during water bubbling has been established at a frequency of 12-40 Hz. The magnitude of variation of Poral during tube phonation in water has also been examined. Several practical variables affect water bubbling during WRT and they should be controlled when using this exercise for voice training.

The present course was designed to provide information about the variables that need to be controlled during WRT based on research findings. Practical demonstrations on how to properly performs WRT are also considered.

Dr. Guzman is a voice pathologist with eighteen years of clinical and academic experience. He received his Ph.D. in Speech Techniques and Vocology from the Tampere University, Finland.  He also holds a certification in vocology from the University of Iowa and National Center for Voice and Speech (USA). Dr. Guzman joined the faculty at the Universidad de los Andes, Department of Communication Sciences and Disorders in 2018 following a 15-year academic career at the University of Chile. He also works as a clinician in the Department of Otolaryngology, Las Condes Clinic, Chile. Moreover, He joined the Tampere University (Finland) as Adjunct Professor in 2018.

Dr. Guzman is an active researcher and author of numerous scientific articles and book chapters related to the underling physiology of semi-occluded vocal tract exercises, physiologic voice therapy, and supraglottic constrictions during singing and speaking voice. Dr. Guzman is frequent speaker and lecturer at national and international meetings on topics related to assessment and management of voice disorders.  He belongs to the editorial board of the Journal of Voice and to the Pan American Vocology association (PAVA) Advisory Board.