Voice therapy (transgender)

Voice feminization refers to the voice change from male to female. It is considered an essential part of care for transgender women.[7] 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.[8]

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 towards femininity, can vary from person to person, and many clients are not satisfied with only a change in fundamental frequency.[9] The efficacy of treatment should therefore be evaluated, not only by acoustic characteristics, but also using the transgender person’s perception of the voice and its femininity.

What is considered a feminine or a masculine voice varies depending on age, region, and cultural norms.[8] 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.[8]

Voice modifications for transgender males typically involve the lowering of the speaking fundamental frequency.[4] Voice therapy is generally not required for transgender men as the effects of testosterone on the larynx result in a deeper pitch.[10] However, testosterone therapy does not always deepen the voice to the person's desired level, and others choose to not undergo hormone replacement therapy (female-to-male) at all.[4] Voice masculinization therapy can help to further lower the pitch of transgender males and address voice problems associated with hormone therapy.[4] Another option for female-to-male clients who wish to further lower their speaking pitch is to undergo vocal surgery (see Surgical Techniques for more details).[11]

A speech-language pathologist (SLP) may be involved in aiding the female-to-male client achieve their desired voice goals, while usually prioritizing the overall health of the voice.[11] Therapy techniques may involve finding the client's most comfortable pitch range, using breath support and relaxation exercises, introducing voice strengthening warm-ups, stabilizing posture and increasing chest resonance.[11]

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,[12] 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.[8] 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.[8] The current pitch-raising vocal surgeries include:

• Cricothyroid approximation (CTA) (The most common procedure[8])
  • This surgery tenses and elongates the vocal folds in order to increase vocal pitch. This is done by bringing the cricoid cartilage closer to the thyroid cartilage with sutures or metal plates. The cricoid cartilage is shifted backward and upward and the thyroid cartilage is moved forward and downward. This mimics cricothyroid muscle contraction that tenses and elongates the vocal folds which causes the pitch to increase.[8][12][13]
• Anterior Glottal Web Formation or Anterior Commissure Advancement
  • This surgery shortens the vibrating length of the vocal folds to raise vocal pitch.[14] The tissue of the anterior part of the vocal folds is removed, and then this tissue is sutured together to form a nonvibrating anterior web.[8]
• Laser assisted voice adjustment (LAVA)
  • In this procedure, microlaryngoscopy (a surgical procedure that looks at the vocal folds in great detail) is done in conjunction with a carbon dioxide (CO₂) laser that vaporizes small portions of the vocal folds. When the vocal fold tissue is in the process of healing and scarring, the vocal folds decrease in mass and increase in stiffness. This results in a rise in vocal pitch.[15]
• Laser Reduction Glottoplasty (LRG)
  • This procedure involves using a CO₂ laser to vaporize the anterior part of the vocal folds. Then the vocal folds are tensed with sutures, causing the pitch to increase.[16][17]

Usually, trans women consider vocal surgery when they feel dissatisfied with voice therapy results, or when they want a more authentic sounding female voice. However, it is important to note that vocal surgery alone may not produce a voice that sounds completely feminine, and voice therapy may still be needed.[18] Although there has been evidence to show that all these surgeries can be effective in increasing vocal pitch as measured by F0, results have been mixed.[12] However, many patients do report being satisfied with the results.[12] Negative effects from these surgeries have been noted, including reduced voice quality, reduced vocal loudness, negative effects on swallowing and/or breathing, sore throat, infections and scarring. A positive effect of surgery can be protecting the voice from damage due to the strain of constantly elevating pitch while speaking. Because of the risks, vocal surgery is often considered a last resort after vocal therapy has been pursued.[8]

As for trans men, it is generally presumed that hormone therapy does successfully masculinize the voice and lower vocal pitch.[19] However, this may not be the case for all trans men. Although it is far less common, surgery to lower vocal pitch does exist, and may be considered if traditional hormone therapy did not adequately lower it. Medialization laryngoplasty (or masculinization laryngoplasty) is a procedure where the vocal fold contours are medially augmented with the injection of silastic implants. This mimics the changes that the vocal folds go through during male puberty, which causes a lower sounding voice.[20]

Therapy may take place in an individual or group setting. The most common focus in transgender voice therapy is pitch raising or lowering; however, other gender markers may be more important for the client to work on.[21] Clients and clinicians should discuss goals of therapy to ensure that they are working together toward the voice that most fits the person's gender identity.[4]

In a review of speech literature, Davies and Goldberg (2006) were unable to find any clear protocols for treating the female to male (transgender man) voice. Based on the protocols they found for treating the male to female (transgender woman) voice, they proposed the following therapeutic techniques for both voice feminization and masculinization:[4]

• Imitation of non-transgender people observed in daily life.
• Progressively complex practice while maintaining good voice quality.
• Vocal flexibility exercises to maintain vocal range and voice quality.
• Motor training.
• Identifying and altering voice qualities when coughing, laughing, and clearing the throat.
• Experimentation with a broad range of voice styles.

While there is some evidence for the effectiveness of voice therapy for transgender people, it is still weak. In a 2012 review by Oates (as referenced in Davies, Papp, and Antoni, 2015) of the literature on transgender voice therapy, 83% of studies were found to be at the lowest level of the evidence hierarchy for evidence-based practice, and the remaining 17% were also at low levels.[21] However, research does show that transgender clients who have had voice therapy have high satisfaction with the results, and there is a strong consensus among speech language pathologists (SLPs) as to what are strong markers of speaker gender in voice.[21]

The most common concern for male-to-female transgender individuals is their pitch and speaking fundamental frequency (SFF) (the average frequency produced in a connected speech sample) because they typically perceive a feminine voice as using a higher pitch. Although pitch is the not the most essential element of voice change for these individuals, it is necessary to raise the SFF to a gender appropriate pitch to help with vocal feminization.[22] A speech-language pathologist will work with the individual to raise their pitch and provide therapeutic exercises.

The first step in therapy is determining the habitual speaking fundamental frequency of the individual using an acoustic analyzing program. This is accomplished through several tasks including sustained phonation of the vowels /i/, /a/ and /u/, reading a standardized passage and producing a spontaneous speech sample. Then the therapist and the individual determine what the target pitch should be, based on the gender acceptable range for cis women (i.e. a socially acceptable pitch based on the average female vocal pitch range). When therapy begins, they establish a starting frequency to work on, that is slightly above the client's SFF.[22] The point is to choose a starting pitch that can be produced without strain or excessive vocal effort.[8] As therapy progresses, the target SFF will gradually increase until the goal has been reached. Progression moves from using the target pitch in a sustained vowel to using it in a 2-5 minute conversation.[22]

Semi-occluded vocal tract (SOVT) techniques may be used to facilitate voice production in the higher pitch range. SOVT techniques include phonating into straws, lip or tongue trilling, and producing multiple speech sounds such as nasals /m/, /n/, voiced fricatives (i.e. /z/, /v/), and high vowels such as /u/ and /i/. There are two exercises that are often used: producing a pitch glide that goes from the middle of the pitch range to the upper pitch range; and a messa di voce exercise, where the voice goes from soft to loud to soft again. SOVT techniques have the individual prolong their voice at a higher pitch, which may help make voice production at a higher, non-habitual pitch easier and more efficient.[8]

Pitch can also be altered through voice resonance modification. The length of the vocal tract affects the resonance of the vocal tract, which in turns affects the pitch. Cis men tend to have vocal tracts that are 10-20% larger than those of cis women, and therefore cis men have a lower vocal tract resonance, and a lower pitch, than cis women. Modifying the length of a vocal tract results in a change in resonance and in pitch, as can be shown by saying the sound “sss” and protruding and retracting the lips. Transgender women can use techniques, such as retracting the lips, to shorten the vocal tract and sound more feminine.[23]

There are two major areas of controversy for professionals working on transgender voice. The first is regarding vocal surgery, and the second is regarding bigender voice therapy.

Professional opinion is mixed regarding the use of vocal surgery.[21] There is currently a lack of outcome data, particularly longitudinal data, for pitch-elevating surgery, and outcomes have not been well-monitored over time.[4] Because of this, some SLPs do not think that phonosurgery is a viable treatment option.[4][21] Others believe it is, and still others believe it should be considered only as a "last resort" after the desired pitch change has not been seen in therapy.[4] Critics cite variability in outcome, lack of outcome data, and reported negative effects like compromised voice quality, decreased vocal loudness, adverse impact on swallowing/breathing, sore throat, wound infection, and scarring as reasons to avoid vocal surgery.[21] Proponents argue that surgery may protect a person's voice from damage caused by repetitive strain to elevate pitch in therapy.[21] Ultimately, the decision to undergo surgery is up to the patient, with input from a knowledgeable physician and SLP.

There is also some controversy regarding the use of a bigender voice. A person may want to have both a masculine and a feminine voice in their vocal repertoire, possibly to fit with their own bigender identity, or to read as a different gender in different contexts.[21] Many clinicians will not train bigender voice, arguing that it decreases the opportunity for practice, and it may be difficult or even damaging to the vocal folds for the person to switch from one voice to another. However, Davies, Papp and Antoni (2015) reference the ability of actors to use different accents and dialects, and people to learn different languages as a sign that training a bigender voice may be a viable treatment goal.[21]

• List of transgender-related topics
• Transgender health care
• Chest register
• Falsetto
• Human voice
• Intonation (linguistics)
• Speech therapy
• Speech pathology
• Vocal fry
• Vocal folds

• World Professional Association for Transgender Health

• University of California, San Francisco Center of Excellence for Transgender Health