Responding to clinical alarms in unfolding simulated clinical scenarios: auditory icons perform better than tonal alarms.

BACKGROUND

The international medical device safety standard IEC 60601-1-8 now recommends use of auditory icon alarms. Auditory icon alarms are alarms that act as metaphors for the problems that they signal. These are compared with traditional tonal alarms.

METHODS

Two sets of three auditory alarms were compared, one consisting of auditory icons and one consisting of variants of older tonal alarms. Volunteer participants were required to monitor three clinical scenarios each lasting 4 min with different problems (cardiac, oxygenation, and technical) occurring during each of these scenarios that triggered alarms multiple times. Participants were required to respond to those alarms while performing a separate vigilance task. Participants were taught the alarms before the tasks, learning the alarms either by the name of the problem (Hazard) or the position of the alarms in the sequence of events (Sequence).

RESULTS

Participants responded more accurately (F=23.48, P<0.05, eta2=0.32) and more quickly (F=20.357, P<0.001, eta2=0.51) to auditory icon alarms than to tonal alarms. This higher performance was not at the expense of performance on the vigilance task. The results showed no effect of learning the sounds as Hazards or as a Sequence.

CONCLUSIONS

Auditory icons are more effective than tonal alarms. New alarms as indicated by the standard should be adopted by manufacturers wherever possible.