Perception of Moving, Sounding Objects by Four-Month-Old Infants

Infants and adults were presented with two moving objects accompanied by a single percussive sound. In different experiments, the sound occurred when one object moved through a particular spatial position, when it abruptly changed its direction of movement, or when it made contact with a rigid surface. Infants responded to the sound—object relationship whenever the sound occurred as the object changed direction, irrespective of its impacts with the surface. Adults, in contrast, responded to the sound—object relationship most clearly when sounds were synchronized with impacts. In infancy, perception of auditory—visual relationships thus depends in part on detection of discontinuities in the movement of a visible object.