Validation of Essential Acoustic Parameters for Highly Urgent In-Vehicle Collision Warnings

Abstract

Objective The aim of this study was to validate the importance of key acoustic criteria for use as in-vehicle forward collision warning (FCW) systems. Background Despite recent advances in vehicle safety, automobile crashes remain one of the leading causes of death. As automation allows for more control of noncritical functions by the vehicle, the potential for disengagement and distraction from the driving task also increases. It is, therefore, as important as ever that in-vehicle safety-critical interfaces are intuitive and unambiguous, promoting effective collision avoidance responses upon first exposure even under divided-attention conditions. Method The current study used a driving simulator to assess the effectiveness of two warnings, one that met all essential acoustic parameters, one that met only some essential parameters, and a no-warning control in the context of a lead vehicle-following task in conjunction with a cognitive distractor task and collision event. Results Participants receiving an FCW comprising five essential acoustic components had improved collision avoidance responses relative to a no-warning condition and an FCW missing essential elements on their first exposure. Responses to a consistently good warning (GMU Prime) improved with subsequent exposures, whereas continued exposure to the less optimal FCW (GMU Sub-Prime) resulted in poorer performance even relative to receiving no warning at all. Conclusions This study provides support for previous warning design studies and for the validity of five key acoustic parameters essential for the design of effective in-vehicle FCWs. Application Results from this study have implications for the design of auditory FCWs and in-vehicle display design.

The Effectiveness of Improving Flight Passengers’ Safety Behaviors by Modifying Auditory Cues

“…The frequency of 0.5 kHz was used as the baseline because it was the lower limit that Patterson (1982) suggested. The number of harmonics was also demonstrated to affect the PUL (Lewis et al, 2018). A sine wave does not have harmonics, and other popular periodic waves have harmonics, among which a triangle wave was not too ear-piercing according to researchers' feedback.…”

“…Hellier and Edworthy (1989) and Hellier et al (1993) studied the effects of acoustic parameters on audio warning PULs. Based on the previous studies, the frequency, number of harmonics, repetition, and length could alter PUL (Baldwin, 2011;Guillaume et al, 2003;Hellier & Edworthy, 1999;Lewis et al, 2018). By modifying these parameters, audio warnings can convey higher PULs and make people believe the situation is urgent and serious.…”

Effects of Auditory Display Types and Acoustic Variables on Subjective Driver Assessment in a Rail Crossing Context

“…Acoustic variables, such as loudness, can be modulated and influence user response to any specific auditory display type (16). In the case of non-verbal auditory signals, pulse duration, base frequency, and interburst interval are important acoustic variables to consider when designing collision warning alerts (17).…”

The effect of a startle-based warning, age, sex, and secondary task on takeover actions in critical autonomous driving scenarios

“…Another study found that an audio warning was effective at prompting drivers to move their hands towards the steering wheel, even in the presence of a visual-manual distracting task ( Morando et al, 2020 ). A study on forward collision warnings (FCW) during manual driving scenarios found that acoustic characteristics of the FCW, such as peak-to-total-time ratio, interburst interval, number of harmonics, frequency, and pulse duration, significantly affect the efficacy of auditory warnings ( Lewis et al, 2017 ). However, many studies testing the efficacy of warning systems are conducted in driving simulators, in which drivers do not experience a real physical perturbation as they would in a real crash avoidance scenario.…”