Improving Auditory Warning Design: Relationship between Warning Sound Parameters and Perceived Urgency

Abstract

This paper presents an experimental study of the effects of individual sound parameters on perceived (psychoacoustic) urgency. Experimental Series 1 showed that fundamental frequency, harmonic series, amplitude envelope shape, and delayed harmonics all have clear and consistent effects on perceived urgency. Experimental Series 2 showed that temporal and melodic parameters such as speed, rhythm, pitch range, and melodic structure also have clear and consistent effects on perceived urgency. The final experiment tested a set of 13 auditory warnings generated by an application of the earlier experimental findings. The urgency rank ordering of this warning set was predicted, and the correlation between the predicted and the obtained order was highly significant. The results of these experiments have a widespread application in the improvement of existing auditory warning systems and the design of new systems, where the psychoacoustic and psychological appropriateness of warnings could be enhanced.

Auditory alerts for in-vehicle information systems: The effects of temporal conflict and sound parameters on driver attitudes and performance

“…The sound characteristics included the sonic urgency of the collision avoidance warning (defined by varying the burst density and loudness) and of the e-mail alert (defined by varying the onset and offset rates). Sonic urgency refers to the urgency of the sound based on the sound parameters that previous research has shown to influence perceived urgency as measured by subjective ratings or reaction time to warnings (Edworthy et al 1991, Hellier et al 1993, Edworthy and Adams 1996, Marshall et al 2001. In this paper, we refer to sonic urgency as 'urgency' and perceived urgency as referred to as 'rated urgency'.…”

“…Mapping highly urgent sounds to collision avoidance warnings and low-urgency sounds to e-mail alerts could reduce the confusion that might arise from temporal conflict. Previous studies have shown that certain sound parameters systematically affect rated urgency (Edworthy et al 1991, but none have examined how it might reduce the demands of interpreting multiple warnings in a realistic driving environment. Beyond the effect on driving performance, inappropriately mapped alerts could also annoy drivers and undermine their acceptance of in-vehicle information systems.…”

The perceived urgency of auditory warning alarms used in the hospital operating room is inappropriate

“…2 For example, Finley and Cohen 2 found that practicing anesthesiologists were unable to identify the clinical situation indicated by alarms that were commonly available in the operating room. The low level of performance existed, presumably, because anesthesiologists were in the habit of deliberately disabling the alarms 1,[3][4][5][6] and so were relatively unfamiliar with them, or because different alarms had similar acoustic qualities. This is hardly an ideal state of affairs given that auditory alarms may substantially increase the speed and appropriateness of a physician's response.…”

Correcting menu usability problems with sound

“…As another example, if the rhythm of a sound is changed (perhaps speeding up or slowing down) this will also demand attention. Edworthy et al suggest other techniques for making sounds attention-grabbing without the use of intensity: High pitch, a wide pitch range, rapid onset and offset times, irregular harmonics and atonal or arrhythmic sounds (for more see Edworthy et al (1989Edworthy et al ( , 1991. The opposites of most of these can be used to make sounds avoidable.…”