This article aims to investigate experimentally the links between prosody and the various domains of linguistics (syntax, semantics, pragmatics). Since the function of prosody is to convey the interpretation of the meaning the speaker wants to give to his utterance, the method that is proposed is to define linguistic models that can be quantified in such a way as to both yield an interpretive strategy of the linguistic contents and to predict a melodic structuring of the lexical framework. Experimental evidence shows links between on the one hand constraints related to the text and the context, and on the other the distribution of models and melodical indices, and allows us to define prosody and more in particular melody, as a subjective locus, where whatever belongs to the linguistic realm enters the realm of pragmatics.

Study of rythmic and temporal properties of babbling of infants aged between 8 and 10 months that were recorded in Paris, London, Hong-Kong and Algiers, shows that, from that age on, the schemes of pitch and syllable organisation tend to approach the characteristic forms of final syllables in the language of the environment. An interlingual comparative study of the phonetic organisation and the syllable structure of babbling shows in the same way that the processes of perceptual selection interact with the motor performance of the infants. So babbling appears as an exercise which reveals a selection by the infants of the forms of the phonetic and phonotactic space that is proper to their language.

It is a well known phenomenon that deaf children generally have many difficulties in acquiring reading and spelling in alphabetic orthographies. It is argued here that these difficulties mainly result from the fact that these children rely on lipreading to perceive spoken language and that their phonological representations are underspecified. Two lines of evidence are presented in support of this view: 1/ an analysis of how deaf children exposed to spoken language only and/or to signed language read and spell; 2/ an analysis of the effect of exposure to visual systems disambiguating lipreading on the development of phonological abilities. It is concludede that deaf children may develop reading and spelling along lines similar to those of hearing children, provided that they are exposed to a linguistic input in which all the phonological contrasts of spoken language are specified.