Efficacy of the Astudillo Method in Voice Harmonization

Objectives:
The purpose of voice harmonization therapy is particularly to adapt acoustic, aerodynamic and prosodic parameters of the voice in order to make them as closely as possible to female or male voices on a perceptual level. In vocal feminization, there are several therapeutic approaches: the symptomatologic, the physiologic and the acoustic. To our knowledge, there is only one vocal feminization method, the Astudillo Method (2019). Nevertheless, no published study has objectified its effectiveness. Also, the aim of this study is to demonstrate the efficiency of this method through comparing acoustic and prosodic parameters collected at the beginning and at the end of the treatment of a trans woman.
Methods
A trans woman received 9 individual voice therapy sessions of 30' per week with the Astudillo method via Skype. Scores of the acoustic measures (using Praat software, Boersma & Weenink, 2017; Phonanium plug-in), of the prosodic measures (using Prosogram tool, Mertens, 2004) and the auto-satisfaction scale (using the Trans Woman Voice Questionnaire, Morsomme et al, 2019) were collected at the beginning, at the end, as well as every two sessions. The acoustic and prosodic measures were gathered on sustained vowels, reading text, and semi spontaneous speech including French intonations. Mean, median, SD, and range of fo and SPL were collected, as well as formant frequencies values (fR1- fR4), vowels length and AVQI index to monitor vocal health.
Results
Significant modifications of the fo values were observed both on sustained vowel (158-258 Hz) and connected speech (155-242Hz) in addition to a slight increase in the fR3 values (2691-2947 Hz). At the prosodic level, a significant increase in melodic variation and intonation movements was observed at the end of the session, on all the tasks (e.g. dialogue reading task 17-48%). Subjectively, the score obtained on the TWVQ post-intervention indicates a significant reduction in vocal dissatisfaction in the participant (69/120-39/120).
Conclusions
The effectiveness of the Astudillo Method was observed in significant modifications of several acoustic, prosodic and auto-satisfaction scores. These results are encouraging. Nevertheless, the study should be extended to a larger transgender population in order to make the results more representative and to evaluate the plus-value of the Astudillo method.