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Objective: To assess whether identifying (or ignoring) learned alarm sounds interferes with performance on a task involving working memory., Background: A number of researchers have suggested that auditory alarms could interfere with working memory in complex task environments, and this could serve as a caution against their use. Changing auditory information has been shown to interfere with serial recall, even when the auditory information is to be ignored. However, previous researchers have not examined well-learned patterns, such as familiar alarms., Method: One group of participants learned a set of alarms (either a melody, a rhythmic pulse, or a spoken nonword phrase) and subsequently undertook a digits-forward task in three conditions (no alarms, identify the alarm, or ignore the alarm). A comparison group undertook the baseline and ignore conditions but had no prior exposure to the alarms., Results: All alarms interfered with serial recall when participants were asked to identify them; however, only the nonword phrase interfered with recall when ignored. Moreover, there was no difference between trained and untrained participants in terms of recall performance when ignoring the alarms, suggesting that previous training does not make alarms less ignorable., Conclusion: Identifying any alarm sound may interfere with immediate working memory; however, spoken alarms may interfere even when ignored., Application: It is worth considering the importance of alarms in environments requiring high working memory performance and in particular avoiding spoken alarms in such environments., (© 2016, Human Factors and Ergonomics Society.)

Objective: We explore how accurately and quickly nurses can identify melodic medical equipment alarms when no mnemonics are used, when alarms may overlap, and when concurrent tasks are performed., Background: The international standard IEC 60601-1-8 (International Electrotechnical Commission, 2005) has proposed simple melodies to distinguish seven alarm sources. Previous studies with nonmedical participants reveal poor learning of melodic alarms and persistent confusions between some of them. The effects of domain expertise, concurrent tasks, and alarm overlaps are unknown., Method: Fourteen intensive care and general medical unit nurses learned the melodic alarms without mnemonics in two sessions on separate days. In the second half of Day 2 the nurses identified single alarms or pairs of alarms played in sequential, partially overlapping, or nearly completely overlapping configurations. For half the experimental blocks nurses performed a concurrent mental arithmetic task., Results: Nurses' learning was poor and was no better than the learning of nonnurses in a previous study. Nurses showed the previously noted confusions between alarms. Overlapping alarms were exceptionally difficult to identify. The concurrent task affected response time but not accuracy., Conclusion: Because of a failure of auditory stream segregation, the melodic alarms cannot be discriminated when they overlap. Directives to sequence the sounding of alarms in medical electrical equipment must be strictly adhered to, or the alarms must redesigned to support better auditory streaming., Application: Actual or potential uses of this research include the implementation of IEC 60601-1-8 alarms in medical electrical equipment.