Auditory Alarms Research Articles

The Effect of Noise Meters Giving Visual and Auditory Alarms Used on Reducing Noise in Neonatal Intensive Care Unit

The Effect of Noise Meters Giving Visual and Auditory Alarms Used on Reducing Noise in Neonatal Intensive Care Unit

High expectancy influences the role of cognitive load in inattentional deafness during landing decision-making

Neglecting a critical auditory alarm is a major obstacle to maintaining a safe environment, especially in aviation. Earlier studies have indicated that tasks with a higher perceptual or cognitive load in the visual modality influence the processing of auditory stimuli. It is unclear, however, whether other factors, such as memory failure, active neglect, or expectancy influence the effect of cognitive load on auditory alarm detection sensitivity during aeronautical decision-making. In this study, we investigated this issue in three laboratory experiments using the technique of signal detection analysis, in which participants were asked to make a landing decision based on indicators of the instrument landing system while also trying to detect an audible alarm. We found that the sensitivity of auditory alarm detection was reduced under conditions of high cognitive load and that this effect persisted even when the auditory detection response occurred first (before the landing decision response) and when the probability of an auditory alarm was 40%. However, the sensitivity of auditory detection was not influenced by cognitive load under high expectancy conditions (60% probability of alarm presentation). Furthermore, the value of the response bias was reduced under high cognitive load conditions when the probability of an auditory alarm was low (20%). With an increase in the level of expectancy (40% and 60% probability of alarm presentation), it was found that cognitive load did not influence the response bias. These findings indicate that visual cognitive load affects the sensitivity to an auditory alarm only at a low expectancy level (20% and 40% probability of alarm presentation). The effect of cognitive load on the sensitivity to an auditory alarm was not due to memory failure or active neglect and the response bias was more sensitive to the expectancy factor.

Evaluating the Effects of Access to Air Quality Data on Household Air Pollution and Exposure—An Interrupted Time Series Experimental Study in Rwanda

In Sub-Saharan Africa, around 80% of residential energy demand is for cooking, with over 760 million people without access to clean cooking fuels and stoves. Particulate matter smaller than 2.5 microns (PM2.5) is a significant pollutant from biomass burning and is linked to respiratory and cardiovascular diseases, as well as adverse pregnancy outcomes. Energy poverty further reinforces gender disparities, keeps children from schools, causes environmental degradation, and interferes with social and economic development. Lack of access to and inadequate adoption of clean cooking stoves and fuels are key barriers to improved air quality. This paper presents a field experiment nested within a large-scale health efficacy trial. The aim of the experiment was to evaluate the effects of access to air quality data and dynamic feedback on indoor air pollution (IAP) and personal exposure. Ninety households in Rwanda were enrolled and provided with an air quality sensor and feedback device, which measured real-time indoor air quality as PM2.5 for sixteen weeks. After six weeks, PM2.5 levels were provided dynamically to households through a display and an auditory alarm. We examined the effects of receiving this feedback on IAP and personal exposure. While access to air quality data did not, in aggregate, improve PM2.5 levels, we did observe several promising correlations worthy of further investigation. The associations between personal exposure or rainfall and increased PM2.5 were reduced after households had access to air quality data. We hypothesized that the behavior changes required to observe these effects—opening doors and windows and moving away from cooking sources—are easy and immediate, in contrast to the costs and complex logistics of entirely eliminating biomass cooking. The types of behavior changes that would directly impact household air pollution and exposure require more than just awareness and willingness to act.

Voice alerting as a medical alarm modality for next-generation patient monitoring: a randomised international multicentre trial

BackgroundAcoustic alarms in medical devices are vital for patient safety. State-of-the-art patient monitoring alarms are indistinguishable and contribute to alarm fatigue. There are two promising new sound modalities for vital sign alarms. Auditory icons convey alarms as brief metaphorical sounds, and voice alerts transmit information using a clear-spoken language. We compared how reliably healthcare professionals identified alarms using these two modalities. MethodsThis investigator-initiated computer-based multicentre simulation study included 28 anaesthesia providers who were asked to identify vital sign alarms in randomised order, once with voice alerts and once with auditory icons. We further assessed time to decision, diagnostic confidence, and perceived helpfulness. We analysed the results using mixed models, adjusted for possible confounders. ResultsWe assessed 14 alarms for each modality, resulting in 392 comparisons across all participants. Compared with auditory icons, healthcare providers had 58 times higher odds of correctly identifying alarms using voice alerts (odds ratio 58.0; 95% confidence interval [CI]: 25.1–133.6; P<0.001), made their decisions about 14 s faster (coefficient –13.9; 95% CI: –15.8 to –12.1 s; P<0.001), perceived higher diagnostic confidence (100% [392 of 392] vs 43% [169 of 392; P<0.001]), and rated voice alerts as more helpful (odds ratio 138.2; 95% CI: 64.9–294.1; P<0.001). The participants were able to identify significantly higher proportions of alarms with voice alerts (98.5%; P<0.001) and auditory icons (54.1%; P<0.001) compared with state-of-the-art alarms (17.9%). ConclusionsVoice alerts were superior to auditory icons, and both were superior to current state-of-the-art auditory alarms. These findings demonstrate the potential that voice alerts hold for patient monitoring.

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.

Nurses’ use of auditory alarms and alerts in high dependency units: A field study

A fieldwork study conducted in six units of a major metropolitan Australian hospital revealed that nurses' attitudes towards alarms are influenced by each unit's physical layout and caseload. Additionally, nurses relied heavily on both non-actionable and actionable alarms to maintain their awareness of the status of their patients' wellbeing, and used auditory alarms beyond the scope of their intended design. Results suggest that before reducing or removing auditory alarms from the clinical environment to improve patient safety, it is important to understand how nurses in different clinical contexts use current alarm systems to extract meaningful information. Such an understanding could guide appropriate alarm reduction strategies and guide alternative design solutions to support nurses' situation awareness during monitoring.

Augmenting Critical Care Patient Monitoring Using Wearable Technology: Review of Usability and Human Factors.

BackgroundContinuous monitoring of the vital signs of critical care patients is an essential component of critical care medicine. For this task, clinicians use a patient monitor (PM), which conveys patient vital sign data through a screen and an auditory alarm system. Some limitations with PMs have been identified in the literature, such as the need for visual contact with the PM screen, which could result in reduced focus on the patient in specific scenarios, and the amount of noise generated by the PM alarm system. With the advancement of material science and electronic technology, wearable devices have emerged as a potential solution for these problems. This review presents the findings of several studies that focused on the usability and human factors of wearable devices designed for use in critical care patient monitoring.ObjectiveThe aim of this study is to review the current state of the art in wearable devices intended for use by clinicians to monitor vital signs of critical care patients in hospital settings, with a focus on the usability and human factors of the devices.MethodsA comprehensive literature search of relevant databases was conducted, and 20 studies were identified and critically reviewed by the authors.ResultsWe identified 3 types of wearable devices: tactile, head-mounted, and smartwatch displays. In most cases, these devices were intended for use by anesthesiologists, but nurses and surgeons were also identified as potentially important users of wearable technology in critical care medicine. Although the studies investigating tactile displays revealed their potential to improve clinical monitoring, usability problems related to comfort need to be overcome before they can be considered suitable for use in clinical practice. Only a few studies investigated the usability and human factors of tactile displays by conducting user testing involving critical care professionals. The studies of head-mounted displays (HMDs) revealed that these devices could be useful in critical care medicine, particularly from an ergonomics point of view. By reducing the amount of time the user spends averting their gaze from the patient to a separate screen, HMDs enable clinicians to improve their patient focus and reduce the potential of repetitive strain injury.ConclusionsResearchers and designers of new wearable devices for use in critical care medicine should strive to achieve not only enhanced performance but also enhanced user experience for their users, especially in terms of comfort and ease of use. These aspects of wearable displays must be extensively tested with the intended end users in a setting that properly reflects the intended context of use before their adoption can be considered in clinical settings.

Ergonomic Auditory Alarm Signals for the Oil and Chemical Processing Industry

OCCUPATIONAL APPLICATIONS Auditory 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.

Spearcon compression levels influence the gap in comprehension between untrained and trained listeners.

Auditory alarms in hospitals are ambiguous and do not provide enough information to support doctors and nurses' awareness of patient events. A potential alternative is the use of short segments of time-compressed speech, or spearcons. However, sometimes it might be desirable for patients to understand spearcons and sometimes not. We used reverse hierarchy theory to hypothesize that there will be a degree of compression where spearcons are intelligible for trained listeners but not for untrained listeners. In Experiment 1, spearcons were compressed to either 20% or 25% of their original duration. Their intelligibility was very high for trained participants, but also quite high for untrained participants. In Experiment 2 each word within each spearcon was compressed to a different degree based on the results of Experiment 1. This technique was effective in creating the desired difference in spearcon intelligibility between trained and untrained listeners. An implication of these results is that manipulating the degree of compression of spearcons "by word" can increase the effect of training so that untrained listeners reliably do not understand the content of the spearcons. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Enhancing cue salience improves aspects of naturalistic time-based prospective memory in older adults with HIV disease.

Older persons living with HIV (PLWH) disease commonly experience failures of time-based prospective memory (PM) in their daily lives. This study examined the benefits of providing strategic supports at encoding, monitoring, and cue detection for naturalistic time-based PM among older PLWH. Participants included 116 older PLWH and 48 seronegatives who completed a baseline neuropsychological evaluation (see Woods et al., 2020), including a laboratory PM experiment that paralleled the design of the current naturalistic study. The naturalistic time-based PM task required participants to press a button on a portable PM response box 4 times per day for 1 month. PLWH were randomly assigned to an unsupported control condition or to an experimental group in which strategic processing was supported at encoding (implementation intentions and visualization), monitoring (content-free cuing), and/or cue detection (auditory alarm). The seronegative participants were all assigned to the unsupported control group. In a model adjusting for age and affective disorders, PLWH who received all three supports in combination demonstrated moderately better naturalistic time-based PM accuracy as compared with PLWH controls. Both the cue detection and combination conditions were associated with markedly more precise response timing on the naturalistic time-based PM task. Supported PM accuracy as measured in the laboratory was positively associated with naturalistic PM accuracy among PLWH in the experimental groups. Providing strategic supports to enhance the cue salience of naturalistic time-based PM tasks may improve both the accuracy and timing with which older PLWH remember to perform time-based intentions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Masking Between Reserved Alarm Sounds of the IEC 60601-1-8 International Medical Alarm Standard: A Systematic, Formal Analysis.

In this work, we systematically evaluated the reserved alarm sounds of the IEC 60601-1-8 international medical alarm standard to determine when and how they can be totally and partially masked. IEC 60601-1-8 gives engineers instruction for creating human-perceivable auditory medical alarms. This includes reserved alarm sounds: common types of alarms where each is a tonal melody. Even when this standard is honored, practitioners still fail to hear alarms, causing practitioner nonresponse and, thus, potential patient harm. Simultaneous masking, a condition where one or more alarms is imperceptible in the presence of other concurrently sounding alarms due to limitations of the human sensory system, is partially responsible for this. In this research, we use automated proof techniques to determine if masking can occur in a modeled configuration of medical alarms. This allows us to determine when and how reserved alarm sound can mask other reserved alarms and to explore parameters to address discovered problems. We report the minimum number of other alarm sounds it takes to both totally and partially mask each of the high-, medium-, and low-priority alarm sounds from the standard. Significant masking problems were found for both the total and partial masking of high-, medium-, and low-priority reserved alarm sounds. We show that discovered problems can be mitigated by setting alarm volumes to standard values based on priority level and by randomizing the timing of alarm tones.

Comparison of Auditory Icon Alarms and Spearcon Sequences for Patient Monitoring

Comparison of Auditory Icon Alarms and Spearcon Sequences for Patient Monitoring

Testing of Auditory Clinical Alarms in ICU/CCU

Almost all medical devices in ICU/CCU have a built-in clinical alarm system to alert when there are changes in a patient’s condition. The objective of this study is to investigate the effectiveness of the existing alarm system in ICU/CCU. Two summative usability tests were conducted to test the effectiveness of existing and new alarm signals based on IEC 60601-1-8:2006 standard. Further formative test is conducted to study the perception of urgency associated with a number of tones in the alarm signals. The findings indicate that the existing auditory alarm signal in ICU/CCU does not indicate the urgency of the alarm conditions. The simulation test indicates that the respondents preferred 282Hz, 500Hz and 800Hz for low, medium and high-risk alarm respectively. The one-sample proportion z test on urgency mapping indicates that the proportion of responses for the highest risk is more than 50% for a single tone test signal. These results show that a single tone test signal being perceived as the highest risk is regardless of frequency. It can be concluded the auditory alarm designed based on this IEC 60608-1-8:2006 standard is not effective. As such it is proposed that the incorporation of the new alarm frequencies and tones will improve the effectiveness of the alarm signal

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.

Remind Me To Remember: A pilot study of a novel smartphone reminder application for older adults with dementia and mild cognitive impairment

ABSTRACT The SmartPrompt is a smartphone-based reminder application informed by a neuropsychological model of functional disability. This laboratory-based pilot study examined the SmartPrompt feasibility, efficacy, and subjective usability using a within-participant, counterbalanced, cross-over design. Ten participants (M age = 80.3 + 8.2; M education = 15.7 + 2.5; 60% female) with mild cognitive impairment or mild dementia completed the Remember to Drink Test, which required preparing a glass of water at four predetermined times, in a SmartPrompt (SP) and Unprompted condition (UP). Written cues and a clock were available in both conditions; however, in the SP, the smartphone presented auditory alarms and visual reminders to obtain the water at specified times and required photo logging. In a separate session, caregivers were trained and tested on configuring the SmartPrompt. Overall, caregivers and participants learned to effectively use the SmartPrompt. Caregivers achieved near-perfect scores on the configuration quiz and responded well to training. Participants completed significantly more Remember to Drink tasks in the SP (93%) than UP (56%); checking the cues/clock decreased by 87% in the SP. Usability ratings were excellent among caregivers and fair among participants. Results indicate that the SmartPrompt holds promise for reducing functional disability in older adults with cognitive difficulties in at-home contexts.

Superior side sound localisation performance in a full-chassis driving simulator

Alerts presented through the auditory modality improve drivers’ crash avoidance performance in driving simulations, but drivers’ ability to accurately localise the source of the auditory alerts is understudied. Because the results of driving simulation studies may hinge on assumptions that sound locations are accurately perceived by drivers, this study used a sound localisation task in a full-chassis driving simulator. Twenty-nine participants engaged in a sound localisation task while seated in the driving simulator. Performance was assessed by sound localisation accuracy, relative directional error, and participant confidence across seven sound sources surrounding the simulator. Performance was best when sounds were presented in left and right cardinal regions, and poorest when presented from the front and rear. Participants were less confident in their localisation judgments when sounds were presented from the rear. Practitioner summary: Drivers’ ability to accurately localise auditory alerts is understudied. Participants performed an auditory localisation task with external sounds while seated in a full-chassis driving simulator. Participants were better detecting sounds from the sides instead of the front and rear. This has implications for external auditory alarms during driving. Abbreviations: ANOVA: analysis of variance; dB: decibel; f: frequency; Hz: hertz; LHD: left hand drive; ms: milliseconds; RTI: realtime technologies; s: seconds; SPL: sound pressure level

Supporting strategic processes can improve time-based prospective memory in the laboratory among older adults with HIV disease.

Older adults with HIV disease demonstrate moderate deficits in time-based prospective memory (PM), which is the strategically demanding ability of remembering to perform a task at a specific time. Using theories from the PM literature, we hypothesized that supporting strategic processes would improve time-based PM in the laboratory among HIV+ older adults. One hundred forty-five HIV+ participants were randomly assigned to a control condition or an experimental group in which strategic processing was supported at encoding (i.e., implementation intentions and visualization), monitoring (i.e., content-free cuing), and/or cue detection (i.e., auditory alarm). The HIV+ control group and 58 seronegative participants completed two ongoing language tasks with a time-based PM requirement. The HIV+ experimental groups underwent counterbalanced time-based PM trials under both control and strategically supported conditions. The HIV+ cue-detection group showed a large within-subjects improvement, which was strongly related to lower scores on separate clinical time-based PM measure and was accompanied by a large reduction in clock-checking behavior. Results also revealed a small within-subjects improvement in time-based PM in the encoding condition. Supporting strategic encoding and cue-detection processes in the laboratory can improve time-based PM deficits in older HIV+ adults, which may inform the development of more naturalistic PM-based interventions to enhance health behaviors. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

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

Given the ease with which the diverse array of environmental sounds can be understood, the difficulties encountered in using auditory alarm signals on medical devices are surprising. In two experiments, with nonclinical participants, alarm sets which relied on similarities to environmental sounds (concrete alarms, such as a heartbeat sound to indicate "check cardiovascular function") were compared to alarms using abstract tones to represent functions on medical devices. The extent to which alarms were acoustically diverse was also examined: alarm sets were either acoustically different or acoustically similar within each set. In Experiment 1, concrete alarm sets, which were also acoustically different, were learned more quickly than abstract alarms which were acoustically similar. Importantly, the abstract similar alarms were devised using guidelines from the current global medical device standard (International Electrotechnical Commission 60601-1-8, 2012). Experiment 2 replicated these findings. In addition, eye tracking data showed that participants were most likely to fixate first on the correct medical devices in an operating theater scene when presented with concrete acoustically different alarms using real world sounds. A new set of alarms which are related to environmental sounds and differ acoustically have therefore been proposed as a replacement for the current medical device standard. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Understanding Metrics of Vehicle Control Take-Over Requests in Simulated Automated Vehicles

This paper derives an effective take-over alarm method for a Society of Automotive Engineers Level 3 automated vehicle using vehicle parameters. An experiment was conducted using a driving simulator. Forty-one subjects participated in two different scenarios: unplanned and planned operational design domain. Subjects drove on a highway at 100 km/h in automated mode. Experiment participants resumed manual control of the vehicle when the alarm was provided in the take-over state. A visual and auditory combined alarm was the most effective in terms of drivers’ cognitive load showing low steering angle deviation and steering reversal rate values compared to the combined visual, auditory, and haptic alarm (p = 0.01 and 0.003). The auditory alarm was the most effective in terms of the quality of the driver’s reaction showing a low maximum acceleration value compared to the combined visual, haptic alarm (p = 0.002). The combined visual, auditory, and haptic alarm was the most effective in terms of post-take-over lateral control showing a low standard deviation lateral position value compared to the haptic alarm (p < 0.001). The auditory and haptic combined alarm was the most effective in terms of post-take-over longitudinal control showing a low number of gas pedal inputs value compared to the haptic alarm (p = 0.002).

The Future of Hospital Sound: Transforming Healthcare Through Sound Experience

Several years ago, a classically trained electronic musician got sick and spent many hours in hospitals. Being a musician, sensitive to sound, she was disturbed by the noise around her: people talking and screaming, doors getting slammed, phones and pagers ringing non-stop, overhead speakers announcing emergencies… and the cacophony of alarms beeping in the dissonance of tritones. Since then, she and her husband (co-author and innovation policy researcher) have embarked on a mission to transform sound experience in hospitals, in collaboration with Johns Hopkins Sibley Memorial Hospital, Stanford Medicine X, TEDMED, and medical device companies. When we listen to people talking about sound, their stories are always more than about sound; they reveal what it means to be a human during the most vulnerable times of their lives. In this article, we explore noise as a symptom of culture, how sound reveals the importance of caring for caregivers, the future of auditory alarm design, and the aesthetic realm in palliative care. These perspectives result from a human-centric (rather than technology-centric) approach to innovation, and how transforming the sound of healthcare means focusing on people and their experiences.