Inside her fifth-floor studio in Lower Manhattan, a vocal instructor stands ramrod-straight on a black rug with flower-and-vine patterns. A slender woman with a wide, expressive mouth, Norma Garbo clasps her hands against her navel and takes a deep breath, her thin frame resembling a stretched bowstring.

Then she thrusts her belly forward. “Gup, gup, gup,” she booms, three distinctive sounds descending in pitch.

Garbo waits for her student to repeat after her. The room echoes with the voice of a six-foot, heavyset 40-year-old woman whose wavy blond hair barely touches her shoulders. That voice is only half as strong as it needs to be, Garbo tells her.

The warm-up exercise is the first step in the training session that brings the two women together every week. For $150 a session, the New York-based voice coach, who also trains singers, helps transgender women—people who were born biologically male, but identify and live as women—attain a passable female voice.

Testosterone injections, which result in a deeper voice, can help transgender men transition more smoothly—hormonal therapy helps to elongate the vocal cords, resulting in a deeper voice. But the hormones used in male-to-female transitions have no effect on the vocal cords, meaning that even after a cosmetic and surgical transition into women, the male-sounding voice often keeps transgender people tied to their old identities.

“I hate being on the phone,” says Sarah, who handles computer networks for a company on Long Island. “I hate leaving voicemail. I hate meeting new people. I hate my voice. It sounds so male-ish.”

So every Saturday morning, Sarah (not her real name), who has been living as a woman for the past nine years, shows up at Garbo’s door for a 45-minute lesson on how to make her speech more feminine.

Sarah spends most of her waking hours carefully watching how she speaks. She feels that if she slips up, the $100,000 she has spent to shed every trace of masculinity—at a doctor’s clinic in Scottsdale, Arizona, to reshape her genitalia; on estrogen shots to adjust her hormones; on electrolysis to get rid of the hair on her face—will count for nothing.

* * *

Today, a thin line of black eyeliner marks Sarah’s eyes, setting off the tint of blue eye shadow on her eyelids. A pink pendant dangles from a gold chain over her bright blue turtleneck, which is tucked into her slim-fitting dark denim jeans, topped off with a black leather jacket.

Sarah has come a long way from her earliest days living as a woman, when she says she smudged more mascara over her face than on her eyelashes, and had to spend two hours every morning staring at a pool of colors in her wardrobe before she could put together an outfit.

She has come even farther from the days she spent casting envious glances at girls in her school in Nassau County, Long Island.

“By second grade, I knew I was in the wrong body,” Sarah says.

“I tried to tell my parents in the fourth grade, then seventh grade and 10th grade,” she says, but “every time I would change the subject, thinking things would go badly.”

Sarah held on to her secret as she finished school, rode on the dot-com boom in the late 1990s to make money as cofounder of a tech firm in Philadelphia, and lost everything at the turn of the century.              

All the while, “I was going crazy,” she says. “I had to tell my parents”—both for her own sanity and so that she could finally begin the transition process.

On a frigid February morning in 2000, as Sarah, then 25, sat beside her mother in her parents’ Volvo, the car jerked to a halt at a busy intersection on Old Country Road.

“My mom lost control of the car when I told her I wanted to transition,” Sarah says.  “We almost had an accident.”

Sarah’s mother went into therapy two days later; her father joined a support group for families of transgender people.

“You’re going to be a freak,” Sarah recalls her father’s words. He suggested that Sarah see a psychiatrist to change her mind.

She waited six years for her parents to come around. “I wanted their acceptance” before having surgery, she says. Eventually, they warmed to the idea, and Sarah scheduled the procedure for the spring of 2007.

Even before she underwent her gender-reassignment surgery, she knew she had to sound like a woman. So in 2006, at the recommendation of a friend from her support group for transgender people, she turned to Garbo.

“I remember our first lesson. I was dressed as a guy. I was wearing jeans and T-shirt. Norma said it would be better if you came dressed as a woman,” she recalls. For the next nine months, Sarah, who was still dressing in male clothes, would visit Garbo carrying a skirt that she would put on before the training began.

After her surgery, Sarah says, the religious organization where she worked at the time fired her. She had taken out a loan to pay for the $24,000 procedure in March 2007; newly unemployed and in debt, she could no longer afford her voice lessons. “After my surgery, I meant to go back to Norma, but finances got crazy,” she says, and the two women fell out of touch.

But this past February, when a colleague introduced Sarah as “he,” the nine years she had spent reinventing herself seemed to fall away.

“I wanted to kill him,” Sarah says, a rasp of impatience in her voice. She contacted Garbo to resume their sessions soon afterwards.

“Their voice is the big red flash that says, ‘I’m a man,’” says Garbo, who has been training transgender women for the past three decades.

Inside the studio, cream-colored walls are adorned with framed gold and platinum records. A black Yamaha piano takes up one corner of the room. Sarah spends the first 15 minutes bending back and forth, rolling her shoulders, swinging her arms and shaking away what Garbo calls “the bad tension.”

“Because of the way they’ve been feeling about themselves since they were little, a lot of them become a little introverted,” Garbo says. “So when they try to change their voice, they get shy and small. I have to train them to let it out.”

The first time a new transgender client walks into her studio, Garbo asks her what she thinks is the most important factor that distinguishes a woman’s voice from that of a man. Nine times out of 10, the reply is “pitch”—how high or low a voice sounds. The pitch of a woman’s voice, they say, is higher.

The answer always draws a quick rebuttal from Garbo, who likes to counter with the example of Lauren Bacall, the classic actress with the famously sultry, low-pitched voice.

“Do you think Bacall had a masculine voice?” Garbo asks. “Oh no,” she lets out in a throaty purr—similar to Bacall’s—to make her point.

It’s more than just the pitch that makes a voice feminine, Garbo says; equally important is the lilt, or the rise and fall of the pitch, which happens through vowels.

“The rule of sound is very simple. Vowels carry pitch. A singer can only sing a vowel,” Garbo says.

It is for this reason that her transgender students first learn to sing.

Garbo heads to the piano and flops herself onto a beige bench to demonstrate the power of vowels: “A-E-I-O-U,” she sings. Sarah watches Garbo’s mouth becoming rounder as her fingers dance on the keys. When Sarah repeats the vowels, she leans back, her golden hoop earrings swinging. The more she lifts her chin—like an opera singer—the higher the sound of her voice.

“You can’t sing an ‘s’, ‘t’, or ‘k’,” Garbo tells her. “If I’m going to move the sounds, we’re only going to do it on vowels. So think, you just came here to learn only five sounds.”

* * *

After studying English and education at Cabrini College and theatre at Villanova University in Philadelphia, Garbo, a native of Freeport, New York, moved to Manhattan in the early 1970s. She trained in voice communication and music for seven years and was soon singing backup for rock legend Billy Joel, reggae star Jimmy Cliff, and disco diva Gloria Gaynor.

One day in 1981, at a house party in the East Village, Garbo’s friend Renee dropped by with her girlfriend, Bonnie, a transgender woman who was struck by Garbo’s background.

“Norma, you’re a voice teacher. My community really needs somebody to help them with their voices,” Garbo says Bonnie told her.

Still early in her career, Garbo wondered if someone whose expertise was training singers would know how to teach transgender women. Drawing on her knowledge of singing and the few research papers on transgender voices that existed at the time, she took on her first client—a psychiatrist who provided counseling to transgender people—in 1983. The same woman soon put her in touch with Leah Cahan Schaefer, a sex researcher and therapist who referred many transgender women to Garbo over the next few years.

Over the years, the vocal instructor used her training in music and theatre to develop her own methods of helping transgender women to find a new voice.

“It’s about allowing the melody in your head and your speaking voice to flow on the same lines,” Garbo says, as Sarah turns away from the piano to move on to the next segment of the session.

On two green cushioned chairs joined together in another corner of the studio, next to shelves stocked with music DVDs and books about voice, sits a giant white easel pad with 10 sentences scribbled in black. Red lines snake up and down through words to indicate lilt.

Her clients learn to work on two kinds of lilts: those that run from one word to another and those that fall within a single word.

Pointing her finger at the first sentence on the pad, Garbo reads aloud, “What a gorgeous day it is,” prolonging the “o” in “gorgeous” and the “a” in “day.” As she emphasizes the syllables, Garbo moves her hand in a wave pattern, her right pinkie glistening with the 1940’s Onyx ring, to indicate how they should rise and fall.

Next is Sarah’s turn to showcase her grasp of lilt.

“What a gorgeous day it is,” she repeats, standing with her arms akimbo, hurrying through the sentence.

Garbo corrects her, moving her right arm to make long twisting curves as she pronounces “day.” “Watch the last word. If you don’t do it nice and slow, you won’t have time to pull all the hills and valleys in it. Right?”

Sarah shuffles her feet and drops her arms, clutching her blue sleeves between her clenched fists, her red nails scratching her palms. She takes a deep breath.

“Day,” Sarah says, in perfect lilt.

“There you go,” Garbo chirps.

The two women talk about the weather a little more before moving on to a roleplay, Garbo’s way of preparing her transgender students for real-life speaking situations.

Today, the two women pretend Garbo is a sales assistant eager to help Sarah pick a cocktail dress at Bloomingdale’s, both of them drawing out their vowels all along.

* * *

There are as many opinions about how to feminize a male voice as there are tissues in the vocal cords.

“It’s really a neurological process,” says Christie Block, a speech-language pathologist who trains transgender women hoping to change their voices. “You have to practice again and again and again and again. You have to live and breathe it.”

At her New York Speech and Voice Lab in Lower Manhattan, Block conducts individual sessions once a week for three months. She lays out realistic plans for beginners: It takes eight visits before the voice starts to seem feminine, provided one practices for 30 minutes every day.

For most voice therapists who train transgender women, the main goal is to help them achieve a higher pitch; they use voice software and guitar tuners to identify the extent to which their clients can modify their voices. The average pitch for an adult woman is 220 Hertz, which means the vocal cords—the two sets of triangular, pearly-white membranes in the voice box that vibrate every time air from the lungs streams through them—open and close 220 times each second. On the other hand, an adult male voice has a pitch of around 120 Hertz.

Block sets a target of 196.

“It allows you to move your pitch around even higher when you speak in conversation,” she explains.  “Pitch is the most important, but it’s not everything. You could change your pitch but still not sound feminine enough.”

That’s where lilt comes into play. Block advises her clients to move their pitch smoothly, imagining it to be a rolling hill rather than a sharp peak.

But she advises caution.

“Some of those ways of talking are really stereotyped,” Block says. “The idea of the ultra-polite woman or that every woman speaks like a valley girl going up all the time—not everybody talks like that.”

But in the process of learning to cast off the male voice, it can be hard to keep gender stereotypes at a distance.

“It’s okay to exaggerate,” Garbo says, “Sometimes the only way to break old habits is to over-exaggerate in the opposite direction.”

In fact, exaggeration often finds its way into Garbo’s teaching methods.

“I use the examples of John Wayne and Marilyn Monroe—the epitomes of ultra-feminine and ultra-masculine voices,” she says. “And then I have my students dissect them.”

“John Wayne talks like this: ‘Hey boys, let’s round ’em up, get the horses out,’” she demonstrates, stiffening her back, lowering her chin, and bobbing her head with each word. “What you’re hearing right now is a disconnect between sounds, almost as if each sound were on its own. A woman doesn’t talk like that. So I take Monroe, who’s almost stupidly feminine. There is fluidity and a lilt. We need to go more towards Monroe, where each sound is connected, and less like Wayne’s choppy staccato.”

During the first few months of Sarah’s initial training with Garbo nine years ago, she rented VHS tapes of Marilyn Monroe classics.

“I used to try not to watch, turn my head away and just listen to her voice,” Sarah says. “I started seeing the difference between how men and women talk.”

Even after Sarah discontinued her vocal training with Garbo back in 2007, she did not stop practicing. On some afternoons during those years, she drove to her parents’ house—a 10-minute drive from the thin-walled apartment she shared with a roommate—when her mother was out shopping. Once she snuck into the basement, Sarah made sure to lock the door and dim the lights. As the sounds of “gup, gup, gup” and “A-E-I-O-U” filled the room, Sarah recalls, she could hear her parents’ two dogs, Roxy and Nelly, scraping against the closed door.

Ever since she resumed her vocal training this year, Sarah has been hard at work. She keeps her teacher’s instructions in mind when she speaks, along with the accompanying gestures Garbo makes.

“Sometimes when I’m talking in the meetings at work, my hands start flying around,” Sarah says, laughing. For once, she allows herself the luxury of not worrying about how it sounds.

“It’s tiring,” she admits. “I’m exhausted, jealous.  Why do I have to do this? A lot of times, I feel like I’m always performing on stage. That’s what it is.”

But she doesn’t forget to stretch her vowels, especially during her interaction with colleagues at work. By three o’clock every day, her cheeks hurt.

Sitting behind her desk by the window in her office, between answering phone calls and emails, Sarah says, she often looks at her reflection.

“I see a blonde, moving her mouth around. I smile. I open my eyes wide. I try to be dramatic.”

Sometimes in moments like these, she remembers her father’s words: “You’re going to be a freak.”

Then she turns back to the window.

“I use it as my mirror,” says Sarah. “I think I have Norma standing behind me. She’s on my side.”