Therapeutic Goals and Acoustic Outcomes in Gender-Affirming Voice Care (GAVC) : Designing ecologically valid groups, integrating pertinent acoustical and physiological measures and assessing the unstandardized

Context: This study addresses a key methodological gap: how to operationalize therapeutic goals without reducing gender diversity to binary voice trajectories. It is part of a doctoral dissertation on gender‑affirming voice care grounded in participatory and community‑based approaches (Cunningham‑Erves et al., 2024) and informed by gender, queer, and trans studies (Enriquez, 2024; Espineira & Thomas, 2019; Salamanca González, 2023). Its broader aim is to integrate therapeutic goals and experiential knowledge into speech‑language therapy while avoiding the pathologization and hyper‑medicalization that have historically shaped trans voice care (Shuster, 2021). Within this framework, the present study introduces a quantitative experimental component to examine how therapeutic goals and transition conditions influence acoustic voice outcomes.
Introduction: Voice is a central marker of identity, conveying emotional states, interactional stance, and social attributes, with gender often perceived as the most salient cue (Azul et al., 2021). Atypical or incongruent voices can elicit negative social judgments, partly due to norms of “vocal beauty” that stigmatize speakers with voice disorders (Verduyckt & Morsomme, 2020). For trans and gender‑diverse people, a voice perceived as inadequate can contribute to anxiety, depressive symptoms, and social withdrawal (Novais Valente Junior & Mesquita de Medeiros, 2022). While most research has focused on long‑term feminization for trans women (Leyns et al., 2021), recent evidence shows that alternating between feminized and masculinized motor voice behaviors (CMVs) is possible without degrading vocal quality or compromising medium‑term acoustic outcomes (Henrotin et al., 2025), opening new clinical possibilities for diverse gender identities and vocal needs.
Methodology: The study compares three therapeutic goal profiles—constant feminization, constant masculinization, and alternation—across ten sessions of trans‑affirmative voice therapy specified using the Rehabilitation Treatment Specification System (Van Stan et al., 2021). A sample of 48 participants (16 per group) is planned based on Hotelling–Lawley Trace power analysis. Data will be analysed using Single‑Case Experimental Design principles, which rely on repeated measures for statistical robustness (Krasny‑Pacini & Evans, 2018). Acoustic measures will be collected across controlled and semi‑spontaneous tasks (Patel et al., 2018).
Discussion: The motivation for presenting this work lies in a methodological challenge: whether grouping participants solely by feminization, masculinization, or alternation adequately captures the diversity of therapeutic goals. More granular subgrouping would improve ecological validity but would require unrealistic sample sizes. Identifying a clinically meaningful grouping variable that preserves statistical power is therefore a central question for discussion.