hormone therapy at all. Voice masculinization therapy can help to further lower the pitch of transgender men and address voice problems associated with hormone therapy. In testosterone replacement therapy vocal folds change faster than larynx. Overdevelopment of vocal folds in an undescended, small larynx can result in a condition named "entrapped vocality" with permanent hoarseness, and lack of passing. Larynx length can be controlled via exercise, making lowering the larynx a useful tool for transgender men in obtaining a passing voice. Other areas that transgender men may benefit from training are embouchure and maintaining high CQ (closed quotient, a quotient of how long the vocal folds are touching to how long the cycle of vibration lasts), responsible for "buzzy" voice quality. A speech-language pathologist (SLP) may be involved in aiding transgender men to achieve their desired voice goals, while usually prioritizing the overall health of the voice. Therapy techniques may involve finding a person's most comfortable pitch range, using breath support and relaxation exercises, introducing voice strengthening warm-ups, stabilizing posture and increasing chest resonance. Another option for transgender men who wish to further lower their speaking pitch is to undergo vocal surgery. Gender perception in voice In the case of AI vocal gender identification examples, key features noted to effect gender perception included fundamental frequency and formant frequency as well as further source related measures including cepstral peak prominence (a rough measure of harmonicity in voice with low values indicating a higher likelihood of dysphonia) and rolloff in energy between the first and second harmonics. A 2020 study in the International Journal of General Medicine noted other factors being involved in gender perception, saying: "a minimum F0 value of 180 Hz required for a voice to be perceived as feminine". Vocal gender presentation can be assigned by speakers even as things like fundamental frequency stay the same, especially where we see formant frequencies changing, which is noted as important for gender presentation alongside fundamental frequency. Vocal surgeries While hormone replacement therapy (HRT) and gender reassignment surgery can cause a more feminine outward appearance for transgender women, they typically do nothing to alter the pitch of an adult voice or to make the voice sound more feminine, unless HRT is started immediately after puberty blockers during teenage years. The existing vocal structure can be surgically altered to raise vocal pitch by shortening the vocal folds, decreasing the whole mass of the