We investigate the effectiveness of sonification (continuous auditory display) for supporting patient monitoring while reducing visual attentional workload in the operating theatre. Non-anaesthetist participants performed a simple continuous arithmetic task while monitoring the status of a simulated anaesthetised patient, reporting the status of vital signs when asked. Patient data were available either on a monitoring screen behind the participant, or were partially or completely sonified. Video captured when, how often and for how long participants turned to look at the screen. Participants gave the most accurate responses with visual displays, the fastest responses with sonification and the slowest responses when sonification was added to visual displays. A formative analysis identifying the constraints under which participants timeshare the arithmetic and monitoring tasks provided a context for interpreting the video data. It is evident from the pattern of their visual attention that participants are sensitive to events with different but overlapping temporal rhythms.