Opening the "Black Box" of Voice Therapy: Investigating CVT-Voice Therapy in pMTD Using Thematic Analysis and the...

Voice therapy is often described as a "black box," with insufficient detail on the active therapeutic components driving change. This study aimed to qualitatively analyze the structure, techniques, and pedagogical features of complete vocal technique-voice therapy (CVT-VT) for the treatment of primary muscle tension dysphonia (pMTD), using thematic analysis and the rehabilitation treatment specification system (RTSS).

Qualitative continuation of a preregistered feasibility and acceptability trial.

Fourteen adults with pMTD were recruited at a National Health Service voice clinic; eleven completed the CVT-VT protocol (average 4.2 sessions) and attended the follow-up research clinic. Fifty-four recorded therapy sessions were transcribed and analyzed through reflexive thematic analysis, followed by consensus classification according to the RTSS framework. Triangulation was achieved using session transcripts, practitioner patient journal notes, and multi-investigator analysis incorporating perspectives of speech-language pathology, singing voice rehabilitation, and vocal pedagogy.

Thematic analysis identified five overarching themes: (1) demystifying voice physiology, (2) (re)coordinating breath and phonation, (3) working toward a clear sound, (4) avoiding uncontrolled constrictions, and (5) designing one's own sound. RTSS consensus analysis specified 10 treatment targets (eg, increased clear voice, improved stamina, patient empowerment, and achieving healthy loudness) and their ingredients, highlighting both functional exercises (eg, voiced fricatives, SOVTEs, epilaryngeal narrowing, and metallic voice production) and pedagogical strategies (eg, structured feedback, motivational scaffolding, promoting growth mindset, and self-efficacy building). CVT-VT emphasized coordinated control of respiratory, phonatory, and resonatory subsystems, with deliberate progression from therapist guidance to patient independence.

CVT-VT represents a functionally oriented, patient-centered intervention for pMTD that integrates explicit pedagogy with deliberate therapeutic practice. Findings highlight the value of qualitative inquiry to examine not only what therapy is delivered, but how it is pedagogically delivered. The findings participate in opening the "black box" of therapy, detailing active components and mechanisms of action, and suggest potential for reduced treatment duration compared with traditional voice therapy. Further evaluation in randomized controlled trials with extended follow-up is warranted.

Clinicaltrials.gov website (NCT05365126 Unique Protocol ID: 19ET004). Registered 06 May 2022.