Searching for meaning in sound: Learning and interpreting alarm signals in visual environments

Auditory Sequences Presented With Spearcons Support Better Multiple Patient Monitoring Than Single-Patient Alarms: A Preclinical Simulation

OBJECTIVE

A study of auditory displays for simulated patient monitoring compared the effectiveness of two sound categories (alarm sounds indicating general risk categories from international alarm standard IEC 60601-1-8 versus event-specific sounds according to the type of nursing unit) and two configurations (single-patient alarms versus multi-patient sequences).

BACKGROUND

Fieldwork in speciality-focused high dependency units (HDU) indicated that auditory alarms are ambiguous and do not identify which patient has a problem. We tested whether participants perform better using auditory displays that identify the relevant patient and problem.

METHOD

During simulated patient monitoring of four patients in a respiratory HDU, 60 non-clinicians heard either (a) IEC risk categories as single-patient alarm sounds, (b) event-specific categories as single-patient alarm sounds, (c) IEC risk categories in multi-patient sequences or (d) event-specific categories in multi-patient sequences. Participants performed a perceptual-motor task while monitoring patients; after detecting abnormal events, they identified the patient and the event.

RESULTS

Participants hearing multi-patient sequences made fewer wrong patient identifications than participants hearing single-patient alarms. Advantages of event-specific categories emerged when IEC risk category sounds indicated more than one potential event. Even when IEC and event-specific sounds indicated the same unique event, spearcons supported better event identification than did auditory icon sounds.

CONCLUSION

Auditory displays that unambiguously convey which patient is having what problem dramatically improve monitoring performance in a preclinical HDU simulation.

APPLICATION

Time-compressed speech assists development of detailed risk categories needed in specific HDU contexts, and multi-patient sound sequences allow multiple patient wellbeing to be monitored.

Auditory and cross-modal attentional bias toward positive natural sounds: Behavioral and ERP evidence

Recently, researchers have expanded the investigation into attentional biases toward positive stimuli; however, few studies have examined attentional biases toward positive auditory information. In three experiments, the present study employed an emotional spatial cueing task using emotional sounds as cues and auditory stimuli (Experiment 1) or visual stimuli (Experiment 2 and Experiment 3) as targets to explore whether auditory or visual spatial attention could be modulated by positive auditory cues. Experiment 3 also examined the temporal dynamics of cross-modal auditory bias toward positive natural sounds using event-related potentials (ERPs). The behavioral results of the three experiments consistently demonstrated that response times to targets were faster after positive auditory cues than they were after neutral auditory cues in the valid condition, indicating that healthy participants showed a selective auditory attentional bias (Experiment 1) and cross-modal attentional bias (Experiment 2 and Experiment 3) toward positive natural sounds. The results of Experiment 3 showed that N1 amplitudes were more negative after positive sounds than they were after neutral sounds, which further provided electrophysiological evidence that positive auditory information enhances attention at early stages in healthy adults. The results of the experiments performed in the present study suggest that humans exhibit an attentional bias toward positive natural sounds.

Discriminating between simultaneous audible alarms is easier with auditory icons

When more than one audible alarm is heard simultaneously, discrimination may be compromised. This experiment compares near-simultaneous clinical alarms in two styles, the first are the tonal 'melodies' from the 2012/2006 version of a global medical device safety standard (IEC 60601-1-8) and the second are the auditory-icon-style recommended in the 2020 version of the same standard. Sixty-six participants were required to identify the meaning and priority of four different clinical alarms for one of the two styles of alarm (between-subjects). Alarms sounded both singly and in pairs (within-subjects). Results showed that the auditory icon alarms outperformed the tonal alarms on all measures except one, both for overall accuracy (recognizing both priority and function) and for partial accuracy (recognizing priority or function but not both). The results add to the growing body of evidence supporting the use of auditory icon alarms in clinical environments.

Ergonomic Auditory Alarm Signals for the Oil and Chemical Processing Industry

OCCUPATIONAL APPLICATIONSAuditory alarm signals are a safety measure that would benefit from improvement across many industries. There is a considerable research base that can be applied to the development and testing of audible alarms, though this is rarely done in practice. We describe a process that can be adopted in any area where audible alarm signals are widespread. A comprehensive approach to updating and improving auditory alarms requires consideration not only of individual alarm sounds but also of how the alarm signals will work together. We show the development and design of alarm signal sets following best practices from acoustic, psychoacoustic, and psychological knowledge to ensure that the resultant alarms are localizable, audible, easy to learn, appropriately urgency-mapped, and differentiable. We also describe benchmarking tests, and a protocol for thinking about how auditory alarm signals might be implemented in control rooms of different sizes.