Adapted from a story by The Washington Post’s Amy Ellis Nutt.

Dena is trying to learn a new voice.

Over the course of the past year, she’s had nearly two dozen training sessions at George Washington University’s Speech and Hearing Center. During that time, she’s managed to lift her pitch by almost an octave, according to Linda Siegfriedt, who directs the directs the Clinical Transgender Voice Program and the Voice Disorders Clinic.

“I am going to say [my new voice] is an 8.5 out of 10,” Dena said. “I may never say it is a 10 because I do feel like there are always things to work on.”

Why is Dena — who asked that her last name not be used — trying to change her voice? She explained that being a transgender woman with a man’s voice can be dangerous.

The problem for transgender women is that finding a feminine voice is no easy task. As The Washington Post reported, testosterone, which transgender men take to build up their muscles and grow facial hair, also increases the size of their vocal folds, making their voices deeper. Estrogen, however, which most transgender women take, can’t shrink the vocal cords.

Most of the differences between male and female voices are not biologically determined, but are learned from a very young age, which means they can also be relearned.

“There is a subtle, but very significant psychological barrier to speaking too femininely,” Dena said. “I did not realize for a long time that many of the speaking patterns I would keep falling back into were unconsciously ingrained in me from childhood as to what a boy and a young man sound like.”

There are only a handful of voice training programs for transgender women in the United States. But they’re needed, experts say, with more and more transgender people wanting to express their identity in the public sphere.

Voice training focuses on five parts of speech: pitch, intonation, volume, articulation and resonance. The vocal tract, which produces sound, travels from the larynx and vocal cords up through the head and out the nose and mouth. A female voice is typically breathier and usually emanates more from the face and nasal cavity. The male voice typically originates in the lower part of the throat or chest.

Voice training for transgender women focuses particularly on three of those five speech characteristics:

• Pitch, which they want to raise

• Oral resonance, which is the sound felt and heard in the front of the face and mouth

• Intonation, which is usually more varied and has more upward patterns for women, as opposed to men, who are more monotone and have downward intonation

Of the five parts to speech, resonance often takes the longest to retrain, according to Josie Zanfordino, who was a speech language pathologist long before she came out as a transgender woman.

A person has to use “the entire toolbox — trachea, nasal passages and where you’re aiming the voice,” said Zanfordinso, who is also the co-founder of the transgender voice and communication clinic at Ithaca College in New York. “The nuance of it, and then taking that voice out into the world where you need to use it, that’s not easy.”

One of the reasons it’s not easy is that learning a new voice also means learning how the voice varies in different situations.

“Think about [talking to a] a romantic partner, a kid or an employer. Your style of communication is not one-dimensional,” said Nicholas Palomares, who teaches in the communications department at the University of California at Davis. “It’s not as predictable as our stereotypes would have us believe.”

Adrienne Hancock, an associate professor at George Washington, said voice training is not just about changing a person’s pitch: “We’re changing how they express themselves.”

She also emphasized that it’s “really important not to impose what I think they would sound like as a woman or what I think makes that voice sound really pretty.”

“We have to let the patient say what they like, and then once they find it, help them develop it,” said Hancock, who is a pioneer in the field, according to many of her professional peers.

Insurance for voice training has always lagged, even under the Affordable Care Act, because companies could classify speech therapy as “optional.” Being part of a university department, Hancock said, allows the Speech and Hearing Center at George Washington to offer clients a sliding scale.

The United States has had a nearly fourfold increase in the number of gender affirmation surgeries between 2000 and the beginning of 2015, according to a February study in the Journal of the American Medical Association, and more than a dozen states, plus the District of Columbia, have instituted laws or mandates against the blanket exclusion of gender-affirming surgeries from insurance benefits packages. Federally, Section 1557 of the Affordable Care Act, known as the Health Care Rights Law, prohibits most insurance companies and health-care providers from discriminating on the basis of gender identity.