Alternative communication in the case of speech impairment

We propose an analysis of some problems which need palliative communication, especially oral palliation in the case of speech impairment as a result of an innate or acquired handicap following two major problems involved in the production of sentences: i) access to a lexical memory, where predictions are useful in order to increase the performance of the communication; ii) building sentences, where prediction seems to be more complicated, due to the role of words constituting sentences in communication. Comparing proposed solutions in severe handicaps of palliative communication, we give some important principles required for the bases of writing systems and the difficulties involved, but also some linguistic structures that they reveal. We underline the need for an appropriate analysis of the language to be produced if we aim for the production of sentences for a text to speech system.