Efficiency of the Astudillo Method in Gender-affirming Voice Modification: Case Study

This study explores the application of a gender-affirming voice care approach based on the Astudillo method. The main objective was to assess the differences between the beginning and end of this approach in terms of auto evaluation, acoustic and prosodic parameters. A transgender woman participated in ten sessions of gender-affirming voice care using the Astudillo Method. Evaluations included auto-evaluation using the Trans Woman Voice Questionnaire, acoustic assessment measuring fundamental frequency ( f o ) and formants ( f R ), and prosodic evaluation using the Prosogram software. Statistical analyses included descriptive statistics and the Wilcoxon test. Significant increases were observed in mean fundamental frequency from 158.11 Hz to 258.54 Hz on sustained vowels and from 158.93 Hz to 255.98 Hz in continuous speech. Formants showed minimal changes, except for a slight increase in f R3 from 2691.25 Hz 2947.88 Hz. Prosodic evaluation demonstrated enhanced intonation variability ( P = 0.0313) and intrasyllabic variation ( P = 0.0313), indicating improved prosodic control and expressiveness. TWVQ scores improved from 69/120 to 39/120, reflecting increased satisfaction with gender-affirming voice care. The Astudillo Method effectively increased fundamental frequency and improved prosodic aspects. Prosodic enhancements were particularly notable, indicating successful modification of intonation patterns toward a more feminine style. These findings support the efficacy of the Astudillo Method in achieving gender-affirming voice modification goals using a compact 10-session protocol, highlighting its potential as a viable option for transgender. Future research should explore long-term outcomes and compare them with other gender-affirming voice modification approaches for comprehensive treatment recommendations.