# Acoustic Specification of Object Properties **Opening (not a real abstract):** A general statement of the ecological approach to perception is that a particular animalenvironment relation or event lawfully structures energy distributions that specify the event that generated them. A given event can, of course, structure varied energy media simultaneously, but how richly? Precise information about geometric properties—the sizes and shapes of objects—has long been assumed to be the province of visual perception. But the foregoing ecological law statement suggests that this limitation is more tradition than necessity. Since an object’s physical parameters and its spatial dimensions determine the acoustic structure it generates when mechanically disturbed, such structure is potentially informative about object properties. We describe research showing that the perception of object properties by sound alone is reliable, surprisingly accurate, **Authors:** [[Carello]]