The influences of listening and speaking on pedestrians' assessments of approaching vehicles

Research suggests a relationship between auditory distraction (such as environmental noises or a vocal cell phone conversation) and a decreased ability to detect and localize approaching vehicles. What is unclear is whether auditory vehicle perception is impacted more by distractions reliant on listening or distractions reliant on speaking (analogous to the two components of a vocal cell phone conversation). In two experiments, adult participants listened for approaching vehicle noises and while performing listening- and speaking-based secondary tasks. Participants were tasked with identifying when they first detect an approaching vehicle and when they no longer felt safe to cross in front of the approaching vehicle. For both experiments, the speaking task resulted in significantly later detection of approaching vehicles and riskier crossing thresholds than in the no-distraction and listening conditions. The listening secondary task significantly differed from the control condition in experiment 1, but not experiment 2. Overall, our results suggest auditory distractions, particularly those reliant on speaking, negatively impact pedestrian safety in situations where visual information is minimal. Results may provide guidance for future research and policy about the safety impacts of secondary tasks.     

Sandstorm animations on rural expressways: The impact of variable message sign strategies on driver behavior in low visibility conditions

Problem: Evolving sandstorms on rural expressways in desert countries impair drivers' contrast vision and increase the risk of serious crashes due to delayed speed adjustments. Intelligent Transport Systems (ITS) such as Variable Message Signs (VMS) conveying warnings can be activated to address drivers’ speed adaptation before entering a low visibility zone. To improve drivers’ understanding of the hazard, a sandstorm animation visualizing turbulent sand and its consequences was designed and compared with a general warning pictogram, which is applied if no specific weather pictogram is available. Moreover, minimum warning distances of the VMS to the low visibility zone were tested (e.g., 300 m or 500 m).MethodSixty-three participants from the State of Qatar drove in a driving simulator through clear, transition, and low visibility conditions on a rural expressway. A repeated analysis of variances was conducted to examine the impact of the two on-road warning displays on driving behavior.ResultsThe results showed that the sandstorm animation was similarly effective as a generic warning pictogram in reducing driving speeds before entering the transition and low visibility zone, irrespective of being displayed 500 m or 300 m away. However, the sandstorm animation resulted in consistent similar speed reductions within the low visibility zone, whereas the generic warning pictogram did either perform better or worse after several encounters with a sandstorm. Drivers did strongly agree that the animation is clearly referring to the issue of low visibility, which can be beneficial for recurring low visibility conditions.Practical applications: 1.) Displaying a sandstorm animation is beneficial for rural expressway sections with recurring degrading visibility and low traffic densities, whereas a warning pictogram can be more effective in speed reductions if drivers expect additional traffic hazards. 2.) Roadway authorities have the flexibility to activate a VMS sandstorm warning even for minimum warning distances.     

Learning a Phonological Contrast Modulates the Auditory Grouping of Rhythm

Perceptual grouping is fundamental to many auditory processes. The Iambic–Trochaic Law (ITL) is a default grouping strategy, where rhythmic alternations of duration are perceived iambically (weak‐strong), while alternations of intensity are perceived trochaically (strong‐weak). Some argue that the ITL is experience dependent. For instance, French speakers follow the ITL, but not as consistently as German speakers. We hypothesized that learning about prosodic patterns, like word stress, modulates this rhythmic grouping. We tested this idea by training French adults on a German‐like stress contrast. Individuals who showed better phonological learning had more ITL‐like grouping, particularly over duration cues. In a non‐phonological condition, French adults were trained using identical stimuli, but they learned to attend to acoustic variation that was not linguistic. Here, no learning effects were observed. Results thus suggest that phonological learning can modulate low‐level auditory grouping phenomena, but it is constrained by the ability of individuals to learn from short‐term training.     

Modeling the effects of perceived intuitiveness and urgency of various auditory warnings on driver takeover performance in automated vehicles

Existing driver models mainly account for drivers’ responses to visual cues in manually controlled vehicles. The present study is one of the few attempts to model drivers’ responses to auditory cues in automated vehicles. It developed a mathematical model to quantify the effects of characteristics of auditory cues on drivers’ response to takeover requests in automated vehicles. The current study enhanced queuing network-model human processor (QN-MHP) by modeling the effects of different auditory warnings, including speech, spearcon, and earcon. Different levels of intuitiveness and urgency of each sound were used to estimate the psychological parameters, such as perceived trust and urgency. The model predictions of takeover time were validated via an experimental study using driving simulation with resultant R squares of 0.925 and root-mean-square-error of 73 ms. The developed mathematical model can contribute to modeling the effects of auditory cues and providing design guidelines for standard takeover request warnings for automated vehicles.     

ASSESSING THE ROLE OF EFFORT REDUCTION IN THE REINFORCING EFFICACY OF TIMEOUT FROM AVOIDANCE

Rats responded on concurrent schedules of shock‐postponement or deletion (avoidance) and timeout from avoidance. In Experiment 1, 3 rats' responses on one lever postponed shocks for 20 s and responses on a second lever produced a 1‐min timeout according to a variable‐interval 45‐s schedule. Across conditions, a warning signal (white noise) was presented 19.5 s, 16 s, 12 s, 8 s, or 4 s before an impending shock. Raising the duration of the warning signal increased both avoidance and timeout response rates. Timeout responding, although positively correlated with avoidance responding, was not correlated with the prevailing shock rate. In Experiment 2, 3 rats' responses on one lever deleted scheduled shocks according to a variable‐cycle 30‐s schedule and responses on a second lever produced a 2‐min timeout as described above. After this baseline condition, the avoidance lever was removed and noncontingent shocks were delivered at intervals yoked to the receipt of shocks in the baseline sessions. Timeout responding decreased when the avoidance lever was removed, even though the shock‐frequency reduction afforded by the timeout remained constant. These results suggest that a key factor in the reinforcing efficacy of timeout is suspension of the requirement to work to avoid shock, rather than the reduction in shock frequency associated with timeout.     

Temporal context in speech processing and attentional stream selection: a behavioral and neural perspective

The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the ‘Cocktail Party’ effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech’s temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of ‘Active Sensing’, emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input.     

ERP correlates of language-specific processing of auditory pitch feedback during self-vocalization

The present study investigated whether the neural correlates for auditory feedback control of vocal pitch can be shaped by tone language experience. Event-related potentials (P2/N1) were recorded from adult native speakers of Mandarin and Cantonese who heard their voice auditory feedback shifted in pitch by −50, −100, −200, or −500 cents when they sustained the vowel sound /u/. Cantonese speakers produced larger P2 amplitudes to −200 or −500 cents stimuli than Mandarin speakers, but this language effect failed to reach significance in the case of −50 or −100 cents. Moreover, Mandarin speakers produced shorter N1 latencies over the left hemisphere than the right hemisphere, whereas Cantonese speakers did not. These findings demonstrate that neural processing of auditory pitch feedback in vocal motor control is subject to language-dependent neural plasticity, suggesting that cortical mechanisms of auditory-vocal integration can be shaped by tone language experience.     

The effect of gender on the N1-P2 auditory complex while listening and speaking with altered auditory feedback

The effect of gender on the N1-P2 auditory complex was examined while listening and speaking with altered auditory feedback. Fifteen normal hearing adult males and 15 females participated. N1-P2 components were evoked while listening to self-produced nonaltered and frequency shifted /a/ tokens and during production of /a/ tokens during nonaltered auditory feedback (NAF), frequency altered feedback (FAF), and delayed auditory feedback (DAF; 50 and 200 ms). During speech production, females exhibited earlier N1 latencies during 50 ms DAF and earlier P2 latencies during 50 ms DAF and FAF. There were no significant differences in N1-P2 amplitudes across all conditions. Comparing listening to active speaking, N1 and P2 latencies were earlier among females, with speaking, and under NAF. N1-P2 amplitudes were significantly reduced during speech production. These findings are consistent with the notions that speech production suppresses auditory cortex responsiveness and males and females process altered auditory feedback differently while speaking.     

事件提示和时间提示对新异干扰的影响—— 来自听视跨通道和听通道的证据

采用Oddball范式考察听视跨感觉通道和听感觉通道中“无关刺激”或“无关属性”的信号提示对新异干扰的影响。实验1和实验2分别比较了听视跨通道和听通道中时间事件提示、时间提示和事件提示三种条件。结果表明：(1)时间提示条件下新异干扰效应消失, 而事件提示条件下新异干扰效应仍存在。无关刺激意外变化引起的靶任务行为受损, 不仅与偏差刺激的小概率和新颖性有关, 而且与干扰刺激与靶子间提示信号关联有关, 这种提示关联中事件发生的提示功能比时间间隔的提示功能更为重要。(2)听通道下新异干扰与视听跨通道结果一致, 无关属性也会起到提示信号作用, 同样事件提示功能比时间提示功能更重要。     

Do temporal processes underlie left hemisphere dominance in speech perception?

It is not unusual to find it stated as a fact that the left hemisphere is specialized for the processing of rapid, or temporal aspects of sound, and that the dominance of the left hemisphere in the perception of speech can be a consequence of this specialization. In this review we explore the history of this claim and assess the weight of this assumption. We will demonstrate that instead of a supposed sensitivity of the left temporal lobe for the acoustic properties of speech, it is the right temporal lobe which shows a marked preference for certain properties of sounds, for example longer durations, or variations in pitch. We finish by outlining some alternative factors that contribute to the left lateralization of speech perception.