"Voice therapy" or "voice training" refers to any non-surgical technique used to improve or modify the human voice. Because voice is a social cue to a person's sex and gender, transgender people may frequently undertake voice training or therapy as a part of gender transitioning in order to make their voices sound more typical of their gender, and therefore increase their likelihood of being perceived as that gender. Having voice and speech characteristics be in agreement with one's gender identity is often important to transgender individuals, whether their goal be feminization, neutralisation or masculinization. Voice therapy can be seen as an act of gender- and identity-affirming care, in order to reduce gender dysphoria and gender incongruence, improve the self-reported wellbeing and health of transgender people, and alleviate concerns over an individual being recognized as transgender. Voice feminization Voice feminization refers to the perception of voice change from masculine to feminine. It is considered an essential part of care for transgender women. Transgender women trying to feminize their voice represent the largest group seeking speech therapy services, therefore, most studies regarding transgender voice have focused on voice feminization, as opposed to voice masculinization. Therapy has been shown to be effective in voice feminization, and the modification of certain voice characteristics, such as fundamental frequency and voice resonance, can help in that effect. Fundamental frequency, closely related to pitch, was initially thought to be the characteristic most effective in voice feminization. Raising the fundamental frequency can help towards voice feminization. However, each person might have different perspectives regarding speech and voice, and therefore the salient characteristics, and their relative impact on femininity, can vary from person to person, and many people are not satisfied with only a change in fundamental frequency. What is considered a feminine or a masculine voice varies depending on age, region, and cultural norms. The changes with the greatest effects towards feminization, based on current evidence, are fundamental frequency and voice resonance. Other characteristics that have been explored include intonation patterns, loudness, speech rate, speech-sound articulation and duration. Voice masculinization Voice modifications for transgender men typically involve the lowering of the speaking fundamental frequency. Voice therapy is generally not required for transgender men as the effects of testosterone on the larynx result in a deeper pitch. However, testosterone replacement therapy does not always deepen the voice to the person's desired level, and others choose to not undergo masculinizing