ABSTRACT
Three important forms of information available to the listener may be identified in any auditory warning: what (semantic), where (location) and immediacy (perceived urgency). The present paper reports a design approach incorporating each form. Warning sounds consisted of broad band noises having a spectral notch in which informative harmonic complexes were inserted. Recordings were made via a dummy head, and were presented dichotically to listeners in a left/right localisation task. The first experiment identified a suitable notched noise component for providing location information in the pulse stimulus. The second experiment required participants to identify simultaneously a distinct tonal signature and the location of the sound when they were presented with one of three tonal types, or one of three compound (tone plus noise) stimuli. Response accuracy and response latency for this dual task were significantly better with the compound than with tone the alone stimuli. Immediacy of compound complex stimuli was investigated in the third experiment. It is suggested that auditory warning design will benefit from the simultaneous provision of what and where forms of information in the sounds.
