I am locked in a quiet, carpeted room, listening to a robotic voice on my iPhone. When the voice pauses, I repeat after it: “Jo’s gentlemanly demeanour amused and set him at his ease.”

This rather odd sentence, along with a few hundred others, form part of a test for a new phone app that will allow people to donate their voices to help other people. VocaliD wants to use speech recordings to create personalised synthetic voices for those who are unable to speak on their own. One day, my voice may be cut up and customised for a person who needs a voice that sounds a bit like mine.

There are millions of people with severe speech impediments because of a stroke, Parkinson’s or cerebral palsy, for example. In the past, a lucky few have had synthetic voices built for them. When movie critic Roger Ebert lost his ability to speak due to cancer, Scottish text-to-speech company CereProc was able to build a substitute that sounded close to his own.

But most people don’t have a rich supply of audio recordings at their disposal to help stitch a new voice together. Generally, they are stuck with generic computerised voices – think Stephen Hawking, who uses an early synthesiser called DECtalk.