Designing and deploying meaningful auditory alarms for control systems

Satellite monitoring and control systems provide the possibility for audible alarms to signal system events that require operators to pay attention and eventually to take action. The audible alarms that are currently in use at ESA control areas are very basic and unfortunately non-discriminating with respect to the events they are signalling. These audible alarms consist of sound files often arbitrarily fished out from the Internet; thus, when they sound they convey no added information about the event that caused it. No considerations whatsoever are made concerning their suitability, ergonomic aspects, or effects of such alarms on operators working on long shifts. Because sounds are prompting a much faster reaction from operators than visual cues, when used efficiently they can also be made to establish criticality, urgency, origin or expected action (think for example on your car alarm that tells you to buckle up or that you are about to bump the car behind you). This paper describes the work performed together with Delft University of Technology and the University of Plymouth to analyse the satellite monitoring problem, to define a sound alarm philosophy that foresees different levels of urgency/criticality associated with typical operator actions based on contextual enquiry in the field, and the corresponding implementation of a library of coherent sounds that include 3 themes of 5 sounds each that map to the levels defined. It will also describe the evaluation of the sounds with operators and how the Cluster mission is implementing a solution to deploy this alarm philosophy and sounds in its dedicated control area, making sure to analyse evolution of operator behaviour before and after the deployment.