title: The Flow and Pressure Relationships in Different Tubes Commonly Used for Semi-occluded Vocal Tract Exercises.
abstract: This experimental study investigated the back pressure (P(back)) versus flow (U) relationship for 10 different tubes commonly used for semi-occluded vocal tract exercises, that is, eight straws of different lengths and diameters, a resonance tube, and a silicone tube similar to a Lax Vox tube. All tubes were assessed with the free end in air. The resonance tube and silicone tube were further assessed with the free end under water at the depths from 1 to 7 cm in steps of 1 cm. The results showed that relative changes in the diameter of straws affect P(back) considerably more compared with the same amount of relative change in length. Additionally, once tubes are submerged into water, P(back) needs to overcome the pressure generated by the water depth before flow can start. Under this condition, only a small increase in P(back) was observed as the flow was increased. Therefore, the wider tubes submerged into water produced an almost constant P(back) determined by the water depth, whereas the thinner straws in air produced relatively large changes to P(back) as flow was changed. These differences may be taken advantage of when customizing exercises for different users and diagnoses and optimizing the therapy outcome.
authors: Voice Research Lab, Department of Biophysics, Palacký University Olomouc, Olomouc, The Czech Republic. Electronic address: pandrade@marjon.ac.uk.
authors: Pedro
authors: P
authors: Amarante Andrade
authors: Faculty of Arts, Psychology and Theology, Åbo Akademi University, Turku, Finland.
authors: Greta
authors: G
authors: Wistbacka
authors: Division of Speech and Language Pathology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet (KI), Stockholm, Sweden.
authors: Hans
authors: H
authors: Larsson
authors: Division of Speech and Language Pathology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet (KI), Stockholm, Sweden.
authors: Maria
authors: M
authors: Södersten
authors: Division of Speech and Language Pathology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet (KI), Stockholm, Sweden.
authors: Britta
authors: B
authors: Hammarberg
authors: Faculty of Arts, Psychology and Theology, Åbo Akademi University, Turku, Finland.
authors: Susanna
authors: S
authors: Simberg
authors: Voice Research Lab, Department of Biophysics, Palacký University Olomouc, Olomouc, The Czech Republic.
authors: Jan G
authors: JG
authors: Švec
authors: Division of Speech and Language Pathology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet (KI), Stockholm, Sweden; Research department of Basic Science and Biomedicine, School of Technology and Health (STH), Royal Institute of Technology (KTH), Stockholm, Sweden.
authors: Svante
authors: S
authors: Granqvist
mesh_terms: D004867:Equipment Design; D006801:Humans; D007818:Laryngeal Diseases / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D007830:Larynx / Q000503:physiopathology*; D008953:Models, Anatomic; D017711:Nonlinear Dynamics; D010699:Phonation; D011312:Pressure; D012828:Silicones; D013016:Sound; D014827:Vocal Cords / Q000503:physiopathology; D014831:Voice; D014834:Voice Training
chemical_list: D012828:Silicones
keywords: Back pressure; Flow; Lax Vox tube; Pressure; Resonance tube; Semi-occluded vocal tract exercises; Straw; Voice therapy