A novel sonification strategy for auditory display of heart rate and oxygen saturation changes in clinical settings

The aim of this study was development of a sonification scheme to convey deviations in heart rate and oxygen saturation from a desired target level.

Maintaining physiologic parameters, such as oxygen saturation, within desired ranges, is challenging in many clinical situations. High rates of false positive alarms in clinical settings limit the utility of the alarms that trigger when thresholds are exceeded. Auditory displays that consider the semantic connotations of sounds and the processing limitations of human perception and cognition may improve monitoring.

Across two experiments, clinical practitioners were tested on their ability to (a) discriminate pairs of sounds (two-note discrimination task), (b) infer and discern the intended physiological connotation of each acoustic attribute (name-the-variable task), and (c) categorize the amount of change in an implied physiological variable into three levels of change: none, small, and large (change-magnitude task).

Considerable variation in performance was observed across the set of practitioners, ranging from near-perfect performance on all tasks, even with no prior exposure to the stimuli, to failure to reach a target accuracy criterion of 87.5% after -80 min of training. On average, performance was well above chance on the name-the-variable and change-magnitude tasks during initial exposure and reached criterion within -20 min of training on each task.

The described sonification strategy may effectively communicate information about current heart rate and oxygen saturation status relative to desired target levels.

The results can be applied to clinical monitoring settings in which a stream of discrete auditory informational items is indicated.