Canadian jazz singer Sophie Milman has a close relationship with her doctor. It makes sense, given she's the person that inserts a steroid directly into Milman's vocal cords with a needle.

Dr. Jennifer Anderson is one of a handful of doctors in Canada that specialize in relieving vocal cord strain, which is increasingly becoming an issue for singers. From opera singers to Blue Rodeo's Jim Cuddy, performers like Milman come to the vocal clinic at the St. Michael's Hospital in Toronto looking for solutions.

"I have had times when I left here in tears," Milman said. "I usually don't cry in front of Jennifer."

The music industry is placing more pressure on singers to perform live and audiences are craving big, bold vocals — a potentially dangerous combination.

Céline Dion and Shakira both recently cancelled concerts because of voice issues. Sam Smith, Adele, and Michael Bublé were all forced to put their careers on pause due to vocal cord strain.

Vibrating 1,000 times a second

It all comes down to the delicate membranes of tissue in a person's throat. As we exhale, air passes over vocal folds that vibrate 100 to 1,000 times a second, creating sound. But when vocal cords are strained, they swell. At first, singers may feel fatigued and their sound can become breathy because the vocal folds no longer close properly.

Anderson examines the state of Milman's vocal cords with an endoscopic camera, looking for signs of swelling. An image of her cords appear on the monitor in the background. (CBC)

Milman remembers when vocal strain caught up with her. Two weeks after giving birth to her daughter, she was back in the studio for a recording session. Not long after, she travelled to Italy to perform. Soon she started feeling off.

"I attributed it all to fatigue and then I found it increasingly difficult to speak, let alone sing," Milman said.

At Anderson's clinic, she was diagnosed with vocal cord swelling. Left untreated, swelling can lead to polyps that can rupture, requiring surgery.

In November, when Milman's vocal cords were swollen, Anderson carefully inserted two drops of a steroid into her vocal cords, using an endoscopic camera to target the affected area.

"It's very site specific. Even one injection will show voice improvement," Anderson said.

As the music industry moves away from physical album sales in favour of streaming, the workload for artist has increased. In 2000, recorded music counted for 53 per cent of the global music industry. By 2016, music sales shrank to 38 per cent with live music accounting for 43 per cent.

As The Weeknd said in an interview with Forbes, "We live in a world where artists don't really make the music like we did in the Golden Age. It's not really coming in until you hit the stage."

Anderson says singers are under a lot of pressure to perform but don't have the required skills to handle the increased workload. (CBC)

But Anderson says many musicians starting out aren't prepared for the demands of touring. They typically wind up in her examination chair after they fear they've done permanent damage to their voices.

"Because they increased their workload so tremendously, their skill set doesn't match that workload," she said.

Musicians like Milman struggle to balance business demands with their health.

"Promoters and presenters and agents they don't care that much about fatigue," she said. "I go to Japan, do 2 shows a night, night after night, jetlagged."

The risk of the big voice

There's another factor causing musicians to go mute: the big voice. Performers like Céline Dion and Adele are lauded for their ability to belt it out, but the crowd-pleasing style can create a big strain.

"As you repeat that, you end up with vocal cord swelling that's not reversible in a short time," Anderson said.

Toronto voice coach Elaine Overholt runs performer and teacher Mark Mazri through exercises to help build stamina and avoid tension in the throat. (Nigel Hunt)

She says the key to avoiding injury is finding an experienced teacher to help an artist develop their skill set.

Voice coach Elaine Overholt says too many musicians head out on the road without survival skills.

"Many performers are thrust out into the world with no training, no even idea how to warm up."

She says it's better to focus on building up your stamina than go under the knife.

Fighting their instincts

Overholt counsels students to save their voices, which leaves singers like Milman fighting their instincts.

"When I get on stage I let it all go," she said. "I want to please the audience and I want to make them happy, so I will push and do everything I can to make them happy in the moment and then I pay for it."

As she prepares for a series of shows in Cuba, however, Milman says she is prepared to take care of her instrument.

She even keeps a picture of her vocal cords on her phone as a reminder.

The obsession doesn't go away. With training and care, she has a better understanding of how to return in good health.