We present in this paper an alternative communication system (hereafter ACS) for handicapped persons. The problem consists in helping people to communicate in any situation with any kind of disability, including some kind of cognitive problems as well. Alternative communication primarily relies on an alternative access to the computer by means of various electronic devices (especially in the case of fully paralyzed people). But this also means the necessity of taking into account the communication situation together with the user characteristics.
The preliminary question when developing an alternative communication system concerns the specification of user need. Communicating does not only consists in producing a message or a text, eventually synthesized with a text-to-speech system. An ACS also needs to propose different kind of communications, including non-verbal ones.
Moreover, such systems have to consider some psychological aspects. In particular in the case of degenerative diseases, new device have to be introduced as new step in the degeneration are crossed. We propose an evolutionary system following users needs and capabilities, avoiding them the feeling of using a new device.
Technically, our system relies on a set of sophisticated and original linguistic resources (lexicon and grammars) allowing word access, word prediction and text composition. It also takes into account different kind of communications, from icons to texts via phonemes and morphemes (useful for example in a word completion process). Finally, it proposes the possibility of a multimodal control of the system. This system is currently under evaluation by several users in real-world situation.