An app to give back voice to laryngeal(throat) cancer patients

Two Czech universities have developed a voice synthesis smartphone application that allows people who lose their voice by undergoing throat cancer surgery to continue speaking with their own voice, even after removal of the organ and vocal cords.

Vlastimil Gular: Laryngeal Cancer patient

This joint project of the University of West Bohemia in Pilsen, Charles University in Prague and two private companies, CertiCon and SpeechTech, was launched less than two years ago. It was named Laryngo Voice. The technology is to use patient voice recordings to create a synthetic one that can be taken out of the phone, tablet or laptop via an app.

At the risk of their vocal cords, precisely located in the larynx, Patients lose the use of their voice. A high-tech process developed by two Czech universities, however, preserves it. More precisely, to simulate it, thanks to vocal recordings made before the operation, which allow to model finely the sound timbre! Thanks to a tablet or a smartphone and a voice synthesis tool, it is possible to talk with patient's family again. And this, with his/her "real" voice!

A common procedure in this type of tumor is laryngectomy or extirpation of the larynx. Patients who are going to undergo this operation, should register their voice reading as many sentences as possible. Then, scientists use statistical models to create a synthetic discourse that can be played on mobile phones or tablets of patients through the app.

A Long Process

It is a long process: patients need to record more than 10 thousand sentences to provide scientists with enough material to produce their synthetic voice, something that makes the task difficult because often this disease demands a quick treatment, limiting the a patient's time to make the recordings. But researchers have found how to reduce the number of records needed, which then goes to 3,500. A number that can even in some cases be reduced to 300.

Advanced statistical models, including networks of artificial neurons, then screen the recordings. Voice synthesis specialist "Jindrich Matousek" who leads this project says - "Speech models are used with certain parameters to generate synthetic speech - the more data we have at the start, the better, but we can achieve decent quality from a relatively limited material,". So far, the University of Pilsen has registered 10 to 15 patients, according to Matousek. In addition to the Czech Republic, Pilsen scientists have also created voice samples synthesized in English, Russian and Slovak.

Silly phrases to drive the algorithm

However, patients requiring ablation of the larynx usually have little time and energy to perform many recordings after becoming aware of the diagnosis. And the words must also be recorded several times because they are pronounced differently according to their place in a sentence. Hence, quite ridiculous pronunciation exercises.

Gular's Story

Vlastimil Gular, who lost his job as an upholsterer because of his health problem, A minor surgery on his vocal cords revealed a throat cancer, which led to the loss of his larynx and, with it, to his voice, planned three weeks later, and was able to record 477 sentences before the surgery. But he recognizes that he was stressed and rather unhappy with the quality of his voice.

(Patients with throat cancer often suffer from dysphonia before surgery, and its effect, with a reduced recorded sample, produces a voice whose sound is unnatural. It's better than nothing, though.)

Now he continues chatting with his own voice instead of the timbre of a robot thanks to the app installed on his phone. Gular is using the app to write what he wanted to say, in his own voice, through a mobile phone.

A dozen laryngeal patients have already benefited from the program. In total, a dozen laryngeal patients registered their voice at Pilsen University. A dozen other people, in good health, also realized.

Also, a few months ago, the Microsoft company created an app for smartphones called Soundscape that allows blind people to navigate independently through the city. It works with headphones connected to the smartphone and the user can set a specific goal, for example, a store, and during the walk hear notices about the names of the streets, intersections and corners. In addition, you can find out from the app which objects are around or in front of it.