Change of speech fundamental frequency explains the satisfaction with voice in response to testosterone therapy in female-to-male gender dysphoric individuals.

Previous studies demonstrated that there is a significant change in speaking fundamental frequency after testosterone therapy in female-to-male gender dysphoric individuals. It is yet an open question how the satisfaction with voice alteration can be predicted because until now it is not clear whether a testosterone therapy is sufficiently effective. The aim of the current study was not only to measure satisfaction with voice, but additionally to detect factors that predict or explain satisfaction with voice after testosterone therapy. Therefore, nine female-to-male gender dysphoric individuals were examined during the first year of testosterone treatment at different points of time. The patients underwent several voice analyses within 1 year and had to fill out several questionnaires concerning their voice, depressive symptoms, quality of life and voice handicap index. Multiple regression analyses were performed to find the factors that explained satisfaction with altered voice after 1 year. The difference of voice frequency in semitones before the treatment and after 1 year is the only significant predictor for satisfaction after 1 year (B = 0.442; SE = 0.049) and more important than the absolute fundamental frequency.

Voice deepening under testosterone treatment in female-to-male gender dysphoric individuals.

Female-to-male gender dysphoric individuals rarely access medical services for voice problems arising out of hormonal treatment leading to "voice reassignment". The aim of this study was a close monitoring of voice deepening in the first year following the commencement of testosterone treatment. Voice recordings from nine female-to-male (FTM) were analyzed with Praat software and values for speaking fundamental frequency (SFF) were calculated. Audio recordings were made prior to and within the first year (mean 55.2 weeks) of testosterone treatment at a mean of 35.4 different time points. The values for speaking fundamental frequency were compared with values taken from 21 biological men with healthy voices. The 10th to 90th percentile range of FTM overlapped with those of biological men after about 36 weeks. The mean SFF change was a decrease of 8.78 seminotes at week 52 and at this point in time no significant difference between SSF in FTM and biological men was found. Testosterone treatment led to significant voice deepening within the first year with the degree of change decreasing over time. Mean SFF change in the first year was almost a sixth and thus less than one octave but nonetheless reached an SFF comparable with biological men.