Getting Better Hospital Alarm Sounds Into a Global Standard

The reserved set of audible alarm signals embodied within the global medical device safety standard, IEC 60601-1-8, is known to be problematic and in need of updating. The current alarm signals are not only suboptimal, but there is also little evidence beyond learnability (which is known to be poor) that demonstrates their performance in realistic and representative clinical environments. In this article, we describe the process of first designing and then testing potential replacement audible alarm signals for IEC 60601-1-8, starting with the design of several sets of candidate sounds and initial tests on learnability and localizability, followed by testing in simulated clinical environments. We demonstrate that in all tests, the alarm signals selected for further development significantly outperform the current alarm signals. We describe the process of collecting considerably more data on the performance of the new sounds than exists for the current sounds, which ultimately will be of use to end users. We also reflect on the process and practice of working with the relevant committees and other practical issues beyond the science, which also need constant attention if the alarms we have developed are to be included successfully in an updated version of the standard

Learning medical alarms whilst performing other tasks.

Two studies are reported which first observe, and then attempt to replicate, the cognitive demands of intensive care unit (ICU) activity whilst concurrently learning audible alarms. The first study, an observational study in an ICU ward, showed that the alarms are very frequent and co-occur with some activities more than others. The three most frequently observed activities observed in the ICU were drugs (calculation, preparation and administration), patient observation and talking. The cognitive demands of these activities were simulated in a second, laboratory-based experiment in which alarms were learned. The results showed that performance in the alarm task generally improved as participants were exposed to more repetitions of those alarms, but that performance decrements were observed in the secondary tasks, particularly when there were two or three of them. Some confusions between the alarms persisted to the end of the study despite prolonged exposure to the alarms, confusions which were likely caused by both acoustic and verbal labelling similarities. PRACTITIONER SUMMARY: The cognitive demands of working in an ICU were observed and simulated whilst alarms were learned. Alarms should generally avoid sharing similar rhythmic (and other) characteristics. The simulation task described here could be used for testing alarm learning without requiring a clinical environment

Can you hear it? Identifying the priority and function of overlapping auditory medical alarms

This paper presents an experimental study that exhibits the differences seen between the recognition of high and moderate priority auditory alarms when played simultaneously. Past research has demonstrated that the current IEC-60601-1-8 alarms used in clinical settings are challenging to identify and learn, and that newly developed auditory icons are easier to discriminate. The current research compares these two types of alarms and measures participant ability to recognise both the function and priority of single sounding and combination sounding alarms. Participants were either assigned to listen to IEC alarms or auditory icons and had to determine the function and priority of each alarm for both single and combination trials. Results display a significant difference between alarm priority and function identification in participants in the auditory icon condition, compared with those in the IEC alarms condition. Participants showed greater overall identification accuracy with auditory icons, for both single sounding and combination sounding trials. A significant difference was also found in priority identification in participants exposed to single sounding IEC alarms, where participants were better at identifying the priority of the IEC alarms but not the function. Explanations for this result are discussed with concern to alarm efficacy. Overall, findings from this study show that auditory icons outperform the current IEC alarms on both function and priority identification, proving to be the superior of the two. Results imply the importance of priority and function recognition in auditory icons when placed in a medical environment, and suggestions for further research are made

The Recognizability and Localizability of Auditory Alarms: Setting Global Medical Device Standards.

Objective Four sets of eight audible alarms matching the functions specified in IEC 60601-1-8 were designed using known principles from auditory cognition with the intention that they would be more recognizable and localizable than those currently specified in the standard. Background The audible alarms associated with IEC 60601-1-8, a global medical device standard, are known to be difficult to learn and retain, and there have been many calls to update them. There are known principles of design and cognition that might form the basis of more readily recognizable alarms. There is also scope for improvement in the localizability of the existing alarms. Method Four alternative sets of alarms matched to the functions specified in IEC 60601-1-8 were tested for recognizability and localizability and compared with the alarms currently specified in the standard. Results With a single exception, all prototype sets of alarms outperformed the current IEC set on both recognizability and localizability. Within the prototype sets, auditory icons were the most easily recognized, but the other sets, using word rhythms and simple acoustic metaphors, were also more easily recognized than the current alarms. With the exception of one set, all prototype sets were also easier to localize. Conclusion Known auditory cognition and perception principles were successfully applied to an existing audible alarm problem. Application This work constitutes the first (benchmarking) phase of replacing the alarms currently specified in the standard. The design principles used for each set demonstrate the relative ease with which different alarm types can be recognized and localized

Mixed speech and non-speech auditory displays: impacts of design, learning, and individual differences in musical engagement

Presented at the 25th International Conference on Auditory Display (ICAD 2019) 23-27 June 2019, Northumbria University, Newcastle upon Tyne, UK.Information presented in auditory displays is often spread across multiple streams to make it easier for listeners to distinguish between different sounds and changes in multiple cues. Due to the limited resources of the auditory sense and the fact that they are often untrained compared to the visual senses, studies have tried to determine the limit to which listeners are able to monitor different auditory streams while not compromising performance in using the displays. This study investigates the difference between non-speech auditory displays, speech auditory displays, and mixed displays; and the effects of the different display designs and individual differences on performance and learnability. Results showed that practice with feedback significantly improves performance regardless of the display design and that individual differences such as active engagement in music and motivation can predict how well a listener is able to learn to use these displays. Findings of this study contribute to understanding how musical experience can be linked to usability of auditory displays, as well as the capability of humans to learn to use their auditory senses to overcome visual workload and receive important information