Background and Problem Statement. Speech training in gender diverse individuals focuses on aspects of communication that strongly influence gender perception. Findings from the literature suggest that a listener's gender perception is determined not only by pitch, but also by other components such as intonation. However, the nature and extent of pitch changes required to alter gender perception are not known. In speech therapy, intonation training is frequently used for speech feminization. However, empirical evidence for this is lacking.~Research questions and/or hypotheses Thisresearch investigates the short- and long-term effects of intonation training on acoustic voice characteristics, gender perception and findings of gender-diverse individuals using a randomized sham-controlled trial (RCT). Based on findings from the literature, (a) gender-congruent values are expected for intonation parameters, in addition (b) assessments of gender that fit the gender identity of the person and (c) an improvement in self-assessment after intonation training in the short and long term. This study will lead to new insights into the relationship between intonation and gender perception and makes an important contribution to the evidence for the use of intonation training.~Research Protocol An RCT will be used. Gender diverse individuals will be recruited through the Ghent University Hospital. Inclusion criteria are: diagnosis of gender dysphoria established by the multidisciplinary gender team, age between 18 and 60 years, normal hearing and Dutch mother tongue. Taking into account the expertise of the research group and the low-threshold recruitment through the gender clinic of UZ Gent, a total of n=20 participants is a very feasible number. Subjects will be randomly assigned to the experimental (intonation training) or control group (receiving a placebo intervention). Randomization will be stratified by age group and baseline speaking fundamental frequency. The experimental group will receive 4 weeks (1h/week) of intonation training with a pre- and post-voice assessment and a follow-up assessment after 8 weeks. The control group will receive sham therapy at a similar duration and frequency, also with a pre- and post-measurement and a follow-up assessment after 8 weeks. The control group will receive 4 more weeks (1 hour/week) of intonation training with a post measurement (due to ethical reasons). The multidimensional speech assessments will be blinded and completed and well-defined training programs will be used. The primary outcome measures are: acoustic intonation parameters, gender perception by listeners and self-assessment and client satisfaction. Linear mixed models with post-hoc pairwise comparisons will be used to analyze the evolution of continuous data within and between groups. ICC models and Cohen's kappa will be used to analyze inter- and intra rater reliability.
The aim of this project is to investigate the short- and the longer-term effect of intonation training on vocal characteristics, listener perceptions and patient related outcome measures (PROMS) in gender diverse people using a randomized sham-controlled trial.