While hormone replacement therapy (HRT) and gender reassignment surgery can cause a more feminine outward appearance for trans 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 folds, or by increasing the tension of the folds. Trans women can undergo surgery to raise their vocal pitch as measured by fundamental frequency (F0), to increase their pitch range and to remove access to lower frequency ranges in their voice. The current pitch-raising vocal surgeries include: