Text-to-speech synthesis, often abbreviated to TTS, is a technology that enables a written text to be converted into speech. TTS has been used widely to provide screen reading for people with visual impairments, and also for users with severe speech impairments. Perhaps the best known user of speech synthesis technology is the physicist Stephen Hawking who suffers from motor neurone disease and uses TTS as his speech has become unintelligible. With the aid of word prediction technology he is able to construct a sentence which he then sends to the built-in TTS system (see further: http://www.hawking.org.uk/the-computer.html).
TTS is also used widely in situations where the user's hands or eyes are busy, for example, while driving navigation systems speak the directions as the vehicle progresses along a route. Another widespread use for TTS is in public announcement systems, for example, at airports or train stations. TTS is also used in phone-based call...