Continuity, fluidity and melodic nature of French speech are achieved through the predominance of the special syllabic structure of CV (consonne + voyelle, i. e. consonant + vowel), thanks in particular to such a unique phenomenon as liaison, which functions within a syntagm (a meaningful and complete speech segment). Over the end of the last century and the beginning of this century, the number of liaison types in French has been markedly decreasing, leading in many cases to the emergence of hiatus. In this paper we will not only examine which types of liaison are affected by these linguistic changes in the dramatic reading and in the opera singing, using the example of Jean Cocteau’s monoplay “The Human Voice”, but also identify the phonetic features and pronunciation deformations of the readers and singers.