Auditory alarms for medical equipment: How do we ensure they convey their meanings?

Abstract

For systems to be effective and to earn their users' trust, their signals must be readily interpreted. An international standard IEC 60601–1–8 was released in 2005 that provides guidelines on how to make auditory alarms on medical electrical equipment more recognisable and discriminable. Since the release of the standard, there have been concerns about the adequacy of its recommendations and, in particular, its proposal that manufacturers should use melodies to distinguish alarms from different sources. The melodies presented in the standard are just suggestions, but the standard does not indicate how an acceptable set of melodies can be established. Moreover, the standard does not require that developers perform thorough testing with representative users before implementing any melodies. The paper reviews studies performed over the last few years that demonstrate that the melodies suggested in IEC 60601–1–8 are ineffective. The paper also critiques suggestions that have been put forward for alternative alarm sounds, using speech synthesis techniques, better urgency mapping, and so on. Finally, criteria for future design and evaluation efforts are indicated.