Jessica Gillard and Michael S Schutz (2013)
Exploring Melodic Structure to Increase Heterogeneity of Auditory Alarm Sets in Medical Devices
Journal of Medical Devices, 7(2):12-13.
Auditory alarms in a medical setting are a useful tool to communicate important information about the status of patients as healthcare professional complete concurrent tasks. To assist device manufacturers and medical staff, the International Electrotechnical Commission (IEC) standardized a set of melodic alarms for eight common medical commands (i.e. the IEC 60601 alarms). Unfortunately, empirical studies of these alarms show they are difficult to learn, hard to remember and are frequently confused [1-3]. Several studies have suggested that these problems may be due to the similarity of IEC alarms insofar as that they have the same length, same rhythm and fall within a narrow pitch range [2,4]. Additionally, studies suggest that by increasing the heterogeneity of alarms within a set, learning, memory and discriminability could be improved [4, 5]. Here we describe an exploratory study in which we looked at multiple factors that could increase heterogeneity. Our initial interest was in amplitude envelope (i.e. the shape of a sound over time), as we have found an improvement in memory associations for sounds with “percussive” (i.e. naturally decaying) envelopes vs. those with “flat” (i.e. artificial-sounding) envelopes in a previous study . This manipulation did not seem to play a role in this context. However, our exploration offers new, detailed information on alarm confusions, insights that can inform future research on alarm design.