Localisable auditory warnings: integral 'where’ and 'what’ components
This paper outlines a research project to design and test localisable auditory warnings, which has encompassed laboratory, simulator and field trials. The tonal components from which most existing auditory warnings are formed are poorly localised by listeners, and as white noise provides for good localisation, the novel design approach described is to combine noise with tonal components to produce an accurately identifiable and localisable auditory warning. Two methods of combining these components are described. A temporally discrete design, where noise and tones are presented as successive pulses, was tested in a driving simulator, and in the field. A second method is described that may provide for additional improvements by the simultaneous presentation of a tonal signature in a spectrally notched noise. Laboratory experiments demonstrated that it is possible to combine a noise and tones in the same auditory warning pulse without any significant loss in the localisation and identification properties of the warning.