PRAGUE - Vlastimil Gular's life took an unwelcome turn a year ago: minor surgery on his vocal cords revealed throat cancer, which led to the loss of his larynx -- and with it, his voice. But the 51-year-old father of four is still chatting away using his own voice rather than the tinny timbre of a robot, thanks to an innovative app developed by two Czech universities. "I find this very useful," Gular said, using the app to type in what he wanted to say, in his own voice, via a mobile phone. "I'm not very good at using the voice prosthesis," he added, pointing at the hole the size of a large coin in his throat. A small silicon device implanted in the throat allows people to speak by pressing the hole with their fingers, to regulate airflow through the prosthesis, and so create sound.