abstract : In the previously published first part, the relationship between phonetic sciences and phonology was discussed in the light of the relationship between form and substance. It seems, however, that the main tendencies of the phonological systems of the world's languages are constrained by production and perception. This hypothesis is discussed within the framework of the « substance- based » linguistic approach suggested simultaneously by Lindblom and by Stevens in 1972. We present several universal tendencies of phonological systems which could be explained by the materiality of sound structures and we discuss them in the light of ontogenic data. Finally the rearticulation between the phonetic sciences, phonology, speech processi...