Developmental differences in auditory detection and localization of approaching vehicles

Hearing water temperature: characterizing the development of nuanced perception of sound sources

Without conscious thought, listeners link events in the world to sounds they hear. We study one surprising example: Adults can judge the temperature of water simply from hearing it being poured. We test development of the ability to hear water temperature, with the goal of informing developmental theories regarding the origins and cognitive bases of nuanced sound source judgments. We first confirmed that adults accurately distinguished the sounds of hot and cold water (pre-registered Exps. 1, 2; total N = 384), even though many were unaware or uncertain of this ability. By contrast, children showed protracted development of this skill over the course of middle childhood (Exps. 2, 3; total N = 178). In spite of accurately identifying other sounds and hot/cold images, older children (7-11 years) but not younger children (3-6 years) reliably distinguished the sounds of hot and cold water. Accuracy increased with age; 11 year old's performance was similar to adults'. Adults also showed individual differences in accuracy that were predicted by their amount of prior relevant experience (Exp. 1). Experience may similarly play a role in children's performance; differences in auditory sensitivity and multimodal integration may also contribute to young children's failures. The ability to hear water temperature develops slowly over childhood, such that nuanced auditory information that is easily and quickly accessible to adults is not available to guide young children's behavior. Adults can make nuanced judgments from sound, including accurately judging the temperature of water from the sound of it being poured. Children showed protracted development of this skill over the course of middle childhood, such that 7-11 year-olds reliably succeeded while 3-6 year-olds performed at chance. Developmental changes may be due to experience (adults with greater relevant experience showed higher accuracy) and development of multimodal integration and auditory sensitivity. Young children may not detect subtle auditory information that adults easily perceive. This article is protected by copyright. All rights reserved.

New Risk Situations Related to Low Noise from Electric Vehicles: Perception of Workers as Pedestrians and Other Vehicle Drivers

Sales of electric and hybrid electric vehicles are increasing steadily worldwide, and consequently their presence increases in city areas. At low speeds, the low levels of noise produced by these vehicles could become a new risk factor for road users. However, the magnitude of the risk has not been accurately determined. In addition, its inclusion in the work environment could pose a new risk that should be managed. Thus, in relation to low noise levels of electric and hybrid vehicles, this study aimed to characterise the risk situations and determine the risk perception of workers as pedestrians and internal combustion engine vehicle drivers coming into contact with these vehicles. The data were extracted from 417 questionnaires filled out by the employees of public service companies who come into contact with electric and hybrid vehicles during their working day in the city of Málaga, in the region of Andalusia, Spain. According to the experiences reported, it seems that the risk due to the low noise levels of electric vehicles is moderate and does not reach alarming levels. These risk situations usually occurred in low speed urban areas, particularly when crossing the road, or in semi-pedestrian areas. Almost half the respondents considered that the electric vehicle poses a risk to other road users because it is more difficult to hear, and they believe it likely that other road users could be injured. Despite that risk, pedestrians did not change their way of walking or moving around the parking areas and other areas of the company. Electric and hybrid electric cars are now required to produce sound when travelling at low speeds. Nevertheless, the effectiveness of this measure should be assessed once implemented and future research should explore alternative non-acoustic measures.

Pedestrian distraction: The effects of road environment complexity and age on pedestrian's visual attention and crossing behavior

INTRODUCTION

Little is known about how characteristics of the environment affect pedestrians' road crossing behavior.

METHOD

In this work, the effect of typical urban visual clutter created by objects and elements in the road proximity (e.g., billboards) on adults and children (aged 9-13) road crossing behavior was examined in a controlled laboratory environment, utilizing virtual reality scenarios projected on a large dome screen.

RESULTS

Divided into three levels of visual load, results showed that high visual load affected children's and adults' road crossing behavior and visual attention. The main effect on participants' crossing decisions was seen in missed crossing opportunities. Children and adults missed more opportunities to cross the road when exposed to more cluttered road environments. An interaction with age was found in the dispersion of the visual attention measure. Children, 9-10 and 11-13 years old, had a wider spread of gazes across the scene when the environment was highly loaded-an effect not seen with adults. However, unexpectedly, no other indication of the deterring effect was found in the current study. Still, according to the results, it is reasonable to assume that busier road environments can be more hazardous to adult and child pedestrians. Practical Applications: In that context, it is important to further investigate the possible distracting effect of causal objects in the road environment on pedestrians, and especially children. This knowledge can help to create better safety guideline for children and assist urban planners in creating safer urban environments.

Assessing pedestrian safety across modalities via a simulated vehicle time-to-arrival task

Pedestrians must use a variety of visual and auditory cues when determining safe crossing opportunities. Although vision has received a bulk of the attention in research on pedestrian safety, the examination of both vision and audition are important to consider. Environmental, intrapersonal, and cognitive qualities of a pedestrian context may limit the use of one or both perceptual modalities. Across two experiments, we examined the impact of perceptual constraints on pedestrian safety by measuring the accuracy of vehicle time-to-arrival estimates in a virtual environment when vehicles were only visible, only audible, or both visible and audible. In both experiments, participants estimated the time-to-arrival of vehicles moving at one of two speeds (8-kph, 40-kph). In the second experiment, we introduced ambient traffic noises to examine the impact of environmentally relevant traffic noises on pedestrian perception. Results suggest seeing a vehicle is more advantageous than hearing a vehicle when interacting with traffic, especially in the presence of ambient sound. Both experiments resulted in more accurate time-to-arrival estimates in the visual and mixed conditions than in the auditory-only condition. Implications for pedestrian safety and future research are discussed.

Accident risk associated with smartphone addiction: A study on university students in Korea

Background and aims The smartphone is one of the most popular devices, with the average smartphone usage at 162 min/day and the average length of phone usage at 15.79 hr/week. Although significant concerns have been made about the health effects of smartphone addiction, the relationship between smartphone addiction and accidents has rarely been studied. We examined the association between smartphone addiction and accidents among South Korean university students. Methods A total of 608 college students completed an online survey that included their experience of accidents (total number; traffic accidents; falls/slips; bumps/collisions; being trapped in the subway, impalement, cuts, and exit wounds; and burns or electric shocks), their use of smartphone, the type of smartphone content they most frequently used, and other variables of interests. Smartphone addiction was estimated using Smartphone Addiction Proneness Scale, a standardized measure developed by the National Institution in Korea. Results Compared with normal users, participants who were addicted to smartphones were more likely to have experienced any accidents (OR = 1.90, 95% CI: 1.26-2.86), falling from height/slipping (OR = 2.08, 95% CI: 1.10-3.91), and bumps/collisions (OR = 1.83, 95% CI: 1.16-2.87). The proportion of participants who used their smartphones mainly for entertainment was significantly high in both the accident (38.76%) and smartphone addiction (36.40%) groups. Discussion and conclusions We suggest that smartphone addiction was significantly associated with total accident, falling/slipping, and bumps/collisions. This finding highlighted the need for increased awareness of the risk of accidents with smartphone addiction.

The impact of walking while using a smartphone on pedestrians' awareness of roadside events

Previous studies have shown that using a cell phone to talk or text while walking changes gait kinematics and encourages risky street-crossing behaviors. However, less is known about how the motor-cognitive interference imposed by smartphone tasks affects pedestrians' situational awareness to environmental targets relevant to pedestrian safety. This study systematically investigated the influence of smartphone use on detection of and responses to a variety of roadside events in a semi-virtual walking environment. Twenty-four healthy participants completed six treadmill walking sessions while engaged in a concurrent picture-dragging, texting, or news-reading task. During distracted walking, they were required to simultaneously monitor the occurrence of road events for two different levels of event frequency. Performance measures for smartphone tasks and event responses, eye movements, and perceived workload and situational awareness were compared across different dual-task conditions. The results revealed that during dual-task walking, the reading app was associated with a significantly higher level of perceived workload, and impaired awareness of the surrounding environment to a greater extent compared with the texting or picture-dragging apps. Pedestrians took longer to visually detect the roadside events in the reading and texting conditions than in the dragging condition. Differences in event response performances were mainly dependent on their salient features but were also affected by the type of smartphone task. Texting was found to make participants more reliant on their central vision to detect road events. Moreover, different gaze-scanning patterns were adopted by participants to better protect dual-task performance in response to the changes in road-event frequency. The findings of relationships between workload, dual-task performances, and allocation strategies for visual attention further our understanding of pedestrian behavior and safety. By knowing how attentional and motor demands involved in different smartphone tasks affect pedestrians' awareness to critical roadside events, effective awareness campaigns might be devised to discourage smartphone use while walking.

Effects of secondary tasks on auditory detection and crossing thresholds in relation to approaching vehicle noises

Research suggests an association between distracting environmental sound stimuli and poorer performance in detecting and localizing approaching vehicles using auditory cues. However, no studies have investigated the distractive potential posed by intrapersonal distractors in the context of pedestrian auditory perception. We examined the effects of holding naturalistic vocal and texting cell phone conversations on participants' auditory detection of approaching vehicles and crossing thresholds in a non-visual simulated setting. Ninety-nine adults were randomly assigned to conditions of vocal conversation, texting conversation, or a control group and completed an auditory vehicle detection task. Participants in the vocal cell phone conversation group detected vehicles at significantly shorter distances than participants in the control group. The concurrence of a secondary task did not affect the distances at which participants deemed vehicles noise too close for them to safely cross (i.e., crossing thresholds). Implications for future research and injury prevention are discussed.

Effect of additional warning sounds on pedestrians' detection of electric vehicles: An ecological approach

Virtually silent electric vehicles (EVs) may pose a risk for pedestrians. This paper describes two studies that were conducted to assess the influence of different types of external sounds on EV detectability. In the first study, blindfolded participants had to detect an approaching EV with either no warning sounds at all or one of three types of sound we tested. In the second study, designed to replicate the results of the first one in an ecological setting, the EV was driven along a road and the experimenters counted the number of people who turned their heads in its direction. Results of the first study showed that adding external sounds improve EV detection, and modulating the frequency and increasing the pitch of these sounds makes them more effective. This improvement was confirmed in the ecological context. Consequently, pitch variation and frequency modulation should both be taken into account in future AVAS design.

Detection and Direction Determination of Approaching Vehicle Noises Among Older Adults

We examined detection and direction determination of auditory cues from a pedestrian environment among a sample of older and younger adults. Review of relevant research suggests normal aging is associated with declines in physical, cognitive, and perceptual abilities. Relatively, few studies have examined the impact of such developmental changes on pedestrian safety among older adults, and none have examined such factors in relation to use of auditory cues. Thirty-five younger and 35 older adults completed cognitive measures and a pedestrian auditory detection task. Some results by speed were similar to past research that examined younger samples. Interactions were discovered between age and speed conditions within the auditory task. Results are discussed in the context of past research and with regard to informing future injury prevention efforts.

How Might People Near National Roads Be Affected by Traffic Noise as Electric Vehicles Increase in Number? A Laboratory Study of Subjective Evaluations of Environmental Noise

We face a likely shift to electric vehicles (EVs) but the environmental and human consequences of this are not yet well understood. Simulated auditory traffic scenes were synthesized from recordings of real conventional and EVs. These sounded similar to what might be heard by a person near a major national road. Versions of the simulation had 0%, 20%, 40%, 60%, 80% and 100% EVs. Participants heard the auditory scenes in random order, rating each on five perceptual dimensions such as pleasant–unpleasant and relaxing–stressful. Ratings of traffic noise were, overall, towards the negative end of these scales, but improved significantly when there were high proportions of EVs in the traffic mix, particularly when there were 80% or 100% EVs. This suggests a shift towards a high proportion of EVs is likely to improve the subjective experiences of people exposed to traffic noise from major roads. The effects were not a simple result of EVs being quieter: ratings of bandpass-filtered versions of the recordings suggested that people’s perceptions of traffic noise were specifically influenced by energy in the 500–2000 Hz band. Engineering countermeasures to reduce noise in this band might be effective for improving the subjective experience of people living or working near major roads, even for conventional vehicles; energy in the 0–100 Hz band was particularly associated with people identifying sound as ‘quiet’ and, again, this might feed into engineering to reduce the impact of traffic noise on people.