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.

More detectable, less annoying: Temporal variation in amplitude envelope and spectral content improves auditory interface efficacy.

Auditory interfaces, such as auditory alarms, are useful tools for human computer interaction. Unfortunately, poor detectability and annoyance inhibit the efficacy of many interface sounds. Here, it is shown in two ways how moving beyond the traditional simplistic temporal structures of normative interface sounds can significantly improve auditory interface efficacy. First, participants rated tones with percussive amplitude envelopes as significantly less annoying than tones with flat amplitude envelopes. Crucially, this annoyance reduction did not come with a detection cost as percussive tones were detected more often than flat tones-particularly, at relatively low listening levels. Second, it was found that reductions in the duration of a tone's harmonics significantly lowered its annoyance without a commensurate reduction in detection. Together, these findings help inform our theoretical understanding of detection and annoyance of sound. In addition, they offer promising original design considerations for auditory interfaces.

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

Auditory alarms are an important component of human-computer interfaces, used in mission-critical industries such as aviation, nuclear power plants, and hospital settings. Unfortunately, problems with recognition, detection, and annoyance continue to hamper their effectiveness. Historically, they appear designed more in response to engineering constraints than principles of hearing science. Here we argue that auditory perception in general and music perception in particular hold valuable lessons for alarm designers. We also discuss ongoing research suggesting that the temporal complexity of musical tones offers promising insight into new ways of addressing widely recognized shortcomings of current alarms.