Andrews hoping artificial vocal cords can restore vocal range

Andrews, 76, who permanently lost her full vocal range after an operation in 1997, chairs a non-profit organisation funding the research and is being treated by a voice doctor collaborating on the project.

She could potentially be one of the first patients to benefit from the injected biogel, which is designed to vibrate in the voice box like a real vocal cord.

Vocal cords consist of two folds of tissue that function in much the same way as the reed in a saxophone. When exhaled air blows through them, they vibrate or "flutter" to produce sounds.

Straining the voice through overuse can create scar tissue, which stiffens the vocal cords and causes the voice to become hoarse and breathy.

Cancer, medical procedures or simply the effects of ageing can lead to similar damage. But currently no treatment exists that can restore vocal cord flexibility.

The vocal cord gel developed by Professor Robert Langer's team at the Massachusetts Institute of Technology (MIT) in Boston is based on a material already used in approved cosmetic creams, medical devices and drugs.

Tested in the laboratory, it has been shown to flutter at 200 times per second, which is about the normal rate for a woman talking.

The gel would be used by injecting it into a patient's vocal cords to replace scar tissue.

"The synthetic vocal cord gel has similar properties as the material found in human vocal cords and flutters in response to air pressure changes, just like the real thing," said Prof Langer.

A report on the research was presented yesterday at the annual meeting of the American Chemical Society in Philadelphia.

Animal studies suggest the material is safe and human trials could begin around the middle of next year, said the scientists.

Andrews became involved after being treated by Professor Steven Zeitels, director of the Massachusetts General Hospital Voice Centre, who is working with the MIT team.

Prof Zeitels, whose other patients include veteran rock singer Steven Tyler, of Aerosmith, and British pop star Adele, said: "About 90% of human voice loss is because of lost pliability.

"I recognised this need in my practice over the years after seeing many patients with voice problems. I went to Bob Langer because I knew he could help design a material that would ultimately help patients speak and sing again."

Andrews chairs a non-profit fund-raising organisation called The Voice Health Institute which is supporting the research. Members of the Institute's advisory board include singing stars Lionel Richie and Roger Daltrey, of the Who.

Prof Langer said: "Julie Andrews has visited our lab several times.

"I think she really wanted to learn about what we were doing and see if there was any way she could help.

"She's just a wonderful person and everybody in our lab really enjoyed interacting with her."

Different versions of the artificial vocal cord could be produced for different patients, depending on how they use their voices, the researchers say.

While a normal speaking voice could be restored by stiffer material, a higher grade more flexible gel would be needed to help singers such as Dame Julie hit high notes.

Because the gel degrades over time, patients might need two to five injections per year.

Speaking on a video showing the artificial vocal cord in action, senior MIT scientist Dr Sandeep Karajanagi said: "What this material tries to replicate is that fluttering that happens to vocal cords. What this demonstrates is that our gel material is soft and elastic enough that it can actually get into motion by using an air pressure as low as our lung can produce, essentially."

Asked if he would like to see Dame Julie treated with the biogel vocal cord, he said: "That's what I'm waiting for. That would be great, if we were able to help Julie Andrews."

In a homage to the British singer, the London Olympics' opening ceremony featured some 30 'Mary Poppins' characters floating down from the sky beneath extended umbrellas.