Even though metadiscourse has recently received considerable attention, most research revolves around written, not spoken, metadiscourse. This book studies spoken metadiscourse in two academic genres in the engineering field, the lecture and the peer seminar. It examines what motivates metadiscourse and how engineering academics resort to different types of metadiscourse when they address different audiences. Based on relevance theory (RT), this study provides a socio-cognitive framework within which metadiscourse is analysed. The author draws on RT’s generic concept of cognitive environment and uses it to describe the academic context in particular. This theoretical perspective provides novel insights into motivations, abilities and preferences of engineering academics when using metadiscourse in the two genres under study.