This paper examines the interpreter’s task as an act of speech in the Saussurrean sense of the term. The simultaneous interpreter is both the receiver of an act of speech, all the components of which he must discern and analyse, and the cospeaker of a parallel (if ever so slightly delayed) act of speech, which must contain everything that was found in the original one. In interpreting the speaker’s words, the interpreter relies upon the coherence and redundancy of the various linguistic and semiological cues and indices given by the speaker. The article also discusses the role of written texts in interpretation and considers their semiological dimension.