BACKGROUND: Trans girls may initiate early puberty blockers once puberty has started in order to prevent the development of masculine secondary sexual characteristics. Depending on how early the puberty blockers are administered, voice may have reached a certain degree of development and have acquired typically male acoustic and phonetic parameters, which can cause discomfort and affect the adolescent's quality of life. PURPOSE: The aim of the present study was to (1) determine if there are differences in discomfort with the self-perceiver voice according to the moment of puberty block (PB), and (2) find a relation between vocal discomfort and variables such a voice phonetic/acoustic characteristics and self-perception of voice. METHOD: A cross-sectional study was carried out. Differences in vocal discomfort between a group of trans girls with early puberty block and a group with late puberty block were compared. The participants were given the Voice Handicap index (VHI-30) and the Trans Women Voice Questionnaire (TWVQ) to assess vocal discomfort. In the same way, their anthropometric, clinical and vocal data, such as FO, were collected. The Kruskal-Wallis test was used to compare the differences in the TWVQ punctuation according to the Tanner stage. RESULTS: The value of the fundamental frequency (FO) was 71.5 Hz higher in the early puberty block group (p <
0.001). The total scores of the questionnaires are higher in the late puberty block group (37.5 points in the TWVQ and 26 points in the VHI-30, p <
0.001 in both cases) Vocal self-perception tends to be more feminine in users with early blocked puberty (p = 0.001). There is a negative correlation between FO and puberty block age (r = 0.669) as well as with the TWVQ score (r = 0.755). CONCLUSION: Early puberty blockers seem to be related to lower score in TWVQ and VHI-30. It could represent less vocal discomfort in trans girls. Acute voice seem to be more frequent in early puberty blocked because Fundamental frequency are significantly higher.