Shifting the onset of a moving sound source: a Fröhlich effect in spatial hearing

When observers are presented with a visual target in motion, they typically remember its onset position to be displaced in the direction of motion. The present study investigated a similar effect in the auditory modality. In a dark anechoic environment, an auditory target (short noise pulses) appeared randomly at a peripheral or a central azimuthal position and moved from left to right or from right to left along the frontal horizontal plane. Relative judgments were made to determine the onset position of motion: Employing a two-alternative forced-choice task, listeners compared the onset position of the target to a 2-s visual reference stimulus presented at the left or right of the auditory onset position. In comparison with stationary targets, the onset positions of moving targets were localized as displaced in the direction of motion. The most prominent displacement occurred when the visual reference stimulus was presented after the auditory motion. With the reference stimulus presented before the auditory motion, the displacement was significantly reduced. Moreover, the displacement was stronger with peripheral than with central onset positions. These findings suggest the existence of a potential analogue of the Fröhlich effect in the auditory modality. An auditory spatial attention mechanism is proposed that may have given rise to the observed pattern of results.