The experiments behind the Tullio phenomenon

BACKGROUND: Professor Pietro Tullio was a director at the Laboratory of Experimental Physiology in Bologna during the early twentieth century. His experimental studies resulted in the description of the Tullio phenomenon, which is characterised by sound-induced vertigo and/or eye movements. OBJECTIVE: The experimental studies behind his contribution to vestibular physiology are described within this paper, as are some of the further developments that have been made.