Synesthesia is a central conception in Marshall McLuhan’s exploration of the relationship between media, culture, and the human sensorium. Jay David Bolter claims synesthesia as one of the effects achieved by hypermedia. However, McLuhan’s notion of synesthesia as the simultaneous interplay of the senses in a ratio fostered by the particular medium or media involved is missing in the theoretics of hypermedia, which relegates all sensory phenomena to visual terms and overlooks the interplay between orality and literacy. Research into synesthesia in art, culture, language, and cognition supports McLuhan’s conception of it as the normal process by which the brain reaches a new equilibrium when one of its functions is outered in a technology. While hypermedia thankfully falls short of mimicking natural synesthesia, interactive multimedia and virtual reality systems attempt to provide a false synesthesia that threatens the role of art and culture in achieving sensory balance.