Simultaneous conference interpretation is considered on the basis of a linguistic (semantic) approach, and a bilingual performance model framework is suggested, based on probability prediction of the sense of the incoming source-language (SL) message by an interpreter. The role of semantic redundancy as a source of semantic prediction is discussed. The results of an experimental study of a probability prediction semantic model of simultaneous interpretation (SI) mechanism lead the author to hypothesize a cumulative dynamic analysis of the semantic structure of the incoming message being subconsciously performed by an interpreter. The conclusions touch on the prospects of further psycholinguistic research in simultaneous interpretation.