The oral entry of texts (dictation machine) is an important field of application for automatic speech recognition, and the first existing prototypes are encouraging the development of such applications. However, some research effort has to be carried out. The facilities that have to be improved, include the size of the available vocabulary and the utterance style (continuous or isolated speech). We are working on such improvements. In this paper, we propose a general overview of the MAUD project currently under devlopment. It is based on four major interacting components: an acoustic phonetic-decoder, a lexical component, a linguistic model and a user interface. MAUD uses a vocabulary made up of the most commonly used words in French and contains about 37000 entries extracted from BDLEX. We discuss first the main features of a dictation machine in the general framework of speech recognition. We demonstrate that the lexical component is one of the most important of our system, intervening as it does at a number of different levels: phonetical, phonological, morphological, syntactic, semantic, etc. We also describe our linguistic level which is probabilistic, based on bi- and tri-class frequencies as well as using a set of grammatical rules