In this article, the authors discuss how on-the-body technology alters a performer's perception and sensation prompting new forms of cross-modal (synesthetic) perception. They outline the nature of the 'intertwining' relationship between the sensual and the sonic, inherent in kinaesonic operations, and examine how the intimacy of on-the-body technology problematizes expression, particularly real-time manipulation. They discuss how the natural movement vocabulary of the body becomes the expressive medium for the generation and manipulation of sound, and how flexible protocols and a fluid interface that can be re-configured for each new piece of work allow the artists to put the body at the expressive and contextual centre of the work. These topics are discussed from the point of view of practice with specific reference to the artists' work with the Bodycoder system and their 2005 work The Suicided Voice.