An experimental study of synthesized speech intelligibility using text created by telecommunication device for the deaf (TDD) users

An experiment that was conducted to assess the feasibility of using automatic text-to-speech translation in a message relay service for the deaf is described. Five conditions manipulated telecommunication device for the deaf (TDD) text to create improvements that could be implemented automatically. The manipulations included preprocessing changes such as expanding abbreviations, use of an automatic spelling corrector, and providing rules to users about how to generate more comprehensible text. The results show that, overall, subjects understood the symbolic speech messages very well and that the text manipulations resulted in improved performance. It is shown that a combined condition, which uses the preprocessing changes, the spelling corrections, and the rules to users, resulted in the best performance. These results indicate that speech synthesis can be a viable alternative to relay operator translation