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

Abstract

Objective: Four sets of eight audible alarms matching the functions specified in IEC 60601-1-8 (2012) 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-(2012), 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 which 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 (2012) 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 a known 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 demonstrates the Medical audible alarms 3 relative ease with which different alarm types can be recognized and localized.Keywords: audition; auditory displays; learning; medical device technologies Precis: Four sets of audible alarms matched to the functions specified in IEC 60601-1-8, a global medical device standard, were designed using known principles of successful audible alarm design. When tested for recognizability and localizability, all sets (with one exception for localizability) outperformed the current alarms specified in the standard. This work represents the first phase of updating the alarms specified in that standard

A Holistic and Collaborative Approach to Audible Alarm Design

“…The use of these sounds creates a raft of problems, including lack of distinctiveness, acoustic aversiveness, and lack of meaning. [15][16][17][18][19][20] Expensive medical devices often remain equipped with the most basic of audible alarms, while smartphones-devices that new medical technologies might wish to emulate-are equipped to provide a near-endless variety of sounds (via ringtones, SMS messages, or other alerts) and are supported by sounding devices that are of sufficient quality for us to identify almost any kind of sound.…”

“…bodies has been open and transparent to anyone who wishes to follow the project. 17,[29][30][31][32] In addition to representing a new, more inclusive way of developing alarms for standards, the sounds that will be described in the revision of 60601-1-8 will be very different from those currently in use. The research indicates that "auditory icons" are much easier to learn and recognize than traditional abstract tones and beeps; therefore, it is expected that alarm sounds with an iconic relation to their sources will be adopted in the new version of the standard.…”

“…The research indicates that "auditory icons" are much easier to learn and recognize than traditional abstract tones and beeps; therefore, it is expected that alarm sounds with an iconic relation to their sources will be adopted in the new version of the standard. 17,29,32 Auditory icons typically are real-world sounds that act as metaphors for the events that they are portraying. For example, a sound that in some way resembles or mimics an actual heartbeat might be an appropriate auditory icon for a cardiovascular sound.…”

Evaluating head-worn displays for alarm prioritisation and situation awareness in multiple-patient contexts

“…A body of research investigating ways to increase the amount of information being conveyed by the auditory displays in hospitals has had some success. Edworthy et al (2017) tested the alarm sounds recommended in the current IEC 60601-1-8 alarm standard against a variety of different auditory displays including earcons (sounds that represent the hazard), word rhythms (sounds that mimic the syllables of words), as well as different prioritization and localization techniques. Their data showed that the current alarm standards required longer to recognize and locate than the newer displays.…”

“…This body of research shows that more informative earcons (short auditory motifs) and speech messages can increase awareness for patients' status. Moreover, well-design auditory 'icons' can improve recognition and localisation compared to the current bedside alarm sounds and other alternatives (Edworthy et al, 2017).…”