Multidimensional coding of auditory icons

Auditory icons – or environmental sounds – have the potential to convey information by non-verbal means quickly and accurately. In addition, human listeners are quick to determine many qualities of an auditory object, such as location, distance, size, and motion, from acoustics of the signal. An experiment tests these two coupled assumptions in a controlled laboratory context. Stimuli consisted of auditory icons “loaded” with information achieved through systematic manipulation of the acoustic parameters pitch, volume ramping, and reverberation. Sixty adult listeners were asked to recognize and describe four auditory icons wherein object size, distance and direction of motion were captured in the parameters of each 1-second sound. Participants were accurate at recognizing and interpreting the icons 70-80% of the time. As hypothesized, recognition rate decreased as the number of parameters needing to be recognized increased. There was a significant effect of icons type and parameter manipulation: dog bark was the most easily recognized icon, and the direction parameter interpreted most accurately. Implications of the findings for applied contexts are discussed.