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Four signal-detection experiments demonstrated robust stimulus-driven, or exogenous, attentional processes in selective frequency listening. Detection of just-above-threshold signal tones was consistently better when the, signal matched the frequency of an uninformative cue tone, even with relatively long cue-signal delays (Experiment 1) or when as few as 1 in 8 signals were at the cued frequency (Experiment 2). Experiments 3 and 4 compared performance with informative and uninformative cues. The involvement of intentional, or endogenous, processes was found to only slightly increase the size of the cuing effect beyond that evident with solely exogenous processes, although the attention band, a measure of how narrowly attention is focused, was found to be wider when cues were informative. The implications for models of auditory attention are discussed.

Three important forms of information available to the listener may be identified in any auditory warning: what (semantic), where (location) and when (perceived urgency). Each form is addressed in the present design study of auditory warning pulses. Recordings were made via a dummy head, and were presented dichotically to listeners in a left/right localization task. The first experiment identified a suitable notched noise component for providing location information in the pulse stimulus. The second experiment required participants to simultaneously identify 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 identification and localization task were significantly better with the compound than with tone alone stimuli. Perceived urgency of compound complex tone plus noise stimuli was investigated in the third experiment. While there may be a trade-off between localization acuity and perceived urgency, the addition of noise components to the auditory warning pulse was shown to enhance the location information available to the listener. It is suggested that some auditory warning designs will benefit from the simultaneous provision of what and where forms of information in the sounds.

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