Because of damage in the central nervous system, certain members of the population with severe speech impairments are not able to acquire sufficient literacy skills. Despite this handicap, they can become effective communicators by using different graphic or symbol systems. One of these non-verbal graphic systems is Blissymbolics. Bliss symbols are a set of simple pictograms, each representing a single object or concept.
In recent years several computer-based tools have been developed to combine Bliss symbols with a speech synthesizer, providing an electronic communication tool for users with disabilities. The Hungarian-speaking Blissvox system was created for this purpose. The users of the program can assemble messages by putting symbols together. The messages are stored automatically and can be recalled and displayed or printed at any time. The system uses the Multivox Hungarian formant synthesizer to utter the messages in a synthetic voice.
Due to the rich morphology of Hungarian, sentences made up from the words representing Bliss symbols are ungrammatical. A linguistic module was developed to transform the string of isolated words of the assembled messages into grammatically correct sentences. This module is comprised of a morphological and a syntactic generator with constrained rules and vocabulary. The paper presents this enhanced Blissvox, giving a general technical description of the modules.
We report on some experiences acquired during the use of Blissvox at the Helping Communication Methodological Center, Budapest, Hungary.