Speech synthesis in augmentative communication

`Augmentative communication´ is a term used generally to refer to the use of speech synthesizers for spoken communication by people who cannot speak with their own voices. There are a number of conditions which can cause such loss of speech. Most of them are the result of physical damage to the voice-production mechanisms. Note that a distinction usually has to be drawn between impared speech and impaired language skills. Someone with a mental disability which affects their language ability will probably never be able to communicate, via speech (natural or synthetic) nor through other modes, such as sign language. So users of augmentative communication generally have physical disabilities rather than metal ones. However, physical disability is rarely specific. It is very common for an impairment which affects the speech apparatus to also affect other parts of the body-a fact which will be expanded on below. The author presents a very brief introduction to this use of synthetic speech. More details can be found in Edwards (1991), along with information regarding its use by blind computer users