This paper describes the development and field evaluation of an Advanced Speech Communication System for Deaf People. The system has two modules. The first one is a Spanish into Spanish Sign Language (LSE: Lengua de Signos Española) translation module made up of a speech recognizer, a natural language translator (for converting a word sequence into a sequence of signs), and a 3D avatar animation module (for playing back the signs). The second module is a Spoken Spanish generator from sign-writing composed of a visual interface (for specifying a sign sequence), a language translator (for generating a Spanish sentence), and finally, a text to speech converter. The system integrates three translation technologies: an example-based strategy, a rule-based translation method and a statistical translator. The field evaluation was carried out in the Local Traffic Office in the city of Toledo (Spain) involving real government employees and deaf people.