that can be tracked down with a stethoscope. save lives, is not speculative or even unusual in hospital, where a stethoscope is a normal part of a doctors equipment. Medical students are taught to listen to tissues rubbing in the lungs, gasses bubbling in the intestines, and blood pumping through veins. Many other indicators, such as body temperature or blood CO2 levels, are measured and shown as graphs. However, a graph can be distracting during visually demanding tasks in an operation, and it is possible to synthesise sounds to represent these indicators instead. Medical students performed better in a simulated operation when eight dynamic variables about the health of the patient were presented as sounds rather than graphs, and better with sounds alone than with both sounds and graphs combined (Fitch and Kramer 1994).