Re-Sounding Alarms: Designing Ergonomic Auditory Interfaces by Embracing Musical Insights

A Spatiotemporal and Multisensory Approach to Designing Wearable Clinical ICU Alarms

In health care, auditory alarms are an important aspect of an informatics system that monitors patients and alerts clinicians attending to multiple concurrent tasks. However, the volume, design, and pervasiveness of existing Intensive Care Unit (ICU) alarms can make it difficult to quickly distinguish their meaning and importance. In this study, we evaluated the effectiveness of two design approaches not yet explored in a smartwatch-based alarm system designed for ICU use: (1) using audiovisual spatial colocalization and (2) adding haptic (i.e., touch) information. We compared the performance of 30 study participants using ICU smartwatch alarms containing auditory icons in two implementations of the audio modality: colocalized with the visual cue on the smartwatch's low-quality speaker versus delivered from a higher quality speaker located two feet away from participants (like a stationary alarm bay situated near patients in the ICU). Additionally, we compared participant performance using alarms with two sensory modalities (visual and audio) against alarms with three sensory modalities (adding haptic cues). Participants were 10.1% (0.24s) faster at responding to alarms when auditory information was delivered from the smartwatch instead of the higher quality external speaker. Meanwhile, adding haptic information to alarms improved response times to alarms by 12.2% (0.23s) and response times on their primary task by 10.3% (0.08s). Participants rated learnability and ease of use higher for alarms with haptic information. These small but statistically significant improvements demonstrate that audiovisual colocalization and multisensory alarm design can improve user response times.

Improving detectability of auditory interfaces for medical alarms through temporal variation in amplitude envelope

BACKGROUND

Auditory interfaces play a vital role in many applications, informing users about both urgent and routine information critical to safety. Unfortunately, problems related to high alarm rates, low reliability, and sound annoyance create barriers to optimising the quality of patient care in perioperative medicine and critical care. Here, we explore how to reduce annoyance and improve detection by manipulating a sound's temporal envelope or the way its energy changes over time.

METHODS

In the first experiment, participants were asked to detect a series of percussive and flat tones presented at six signal-to-noise ratios while performing a concurrent speech comprehension task. In the second experiment, different participants were asked to evaluate the relative annoyance of these same sounds.

RESULTS

Relative to industry-standard flat tones, percussive tones were significantly less annoying and more detectable. Although more detectable, percussive tones did not impair concurrent speech comprehension.

CONCLUSIONS

Temporal variation in amplitude envelope represents a promising path towards improving auditory interfaces for patient monitoring. By using temporally variable sounds, auditory interfaces can be more effective in alerting users. This is important for safety-critical areas, such as medical alarms, where annoyance often limits efficacy. As this manipulation can preserve the pitch and rhythm of tone sequences, it is compatible with users' pre-existing knowledge of current alarms.

Loud Auditory Distractors Are More Difficult to Ignore After All

Abstract. Working memory performance is markedly disrupted when task-irrelevant sound is played during item presentation or retention. In a preregistered replication study, we systematically examined the role of intensity in two types of auditory distraction. The first type of distraction is the changing-state effect (i.e., increased disruption by changing-state relative to steady-state sequences). The second type is the auditory deviant effect (i.e., increased disruption by auditory deviant relative to steady-state sequences). In previous experiments, the changing-state effect was independent of intensity. Whether a deviation in intensity leads to an increase in disruption has not yet been examined. We replicated the classic finding that the increased disruption by changing-state relative to steady-state sequences is independent of intensity. Contrary to previous studies, we found an unexpected main effect of intensity. Steady-state and changing-state sequences presented at 75 dB(A) were more disruptive than presented at 45 dB(A), suggesting that intensity plays a more important role than previously assumed in the disruption of working memory performance. Furthermore, we tested the prediction of the violation of expectancy account, according to which deviant distractors at a lower and higher intensity than the rest of the sequence should be equally disruptive. Our results were consistent with this prediction.

Decaying amplitude envelopes reduce alarm annoyance: Exploring new approaches to improving auditory interfaces

Auditory alarms offer great potential for facilitating human-computer interactions in complex, rapidly changing environments. They are particularly useful in medical settings, where in theory they should afford communication in emergency rooms, operating theatres, and hospitals around the world. Unfortunately, the sounds typically used in these devices are problematic, and researchers have documented numerous shortcomings. Their ubiquity means that even incremental improvements can have significant benefits for patient care. However, solutions have proven challenging for multiple reasons-including issues of backward compatibility inherent in changing any standard. Here we present a series of three experiments showing that manipulations to one specific, understudied property can significantly lower alarm annoyance without harming learning or memory-while preserving an alarm's melodic and rhythmic structure. These results suggest promising new directions for improving the hospital's soundscape, where evidence of problems related to sound are increasingly recognized as affecting medical outcomes as well as physician well-being.