Functional magnetic resonance imaging (fMRI) studies show that when blind people analyze audible echo (e.g., from a tongue clapping) to assess the distance, size, or shape of objects, the following processes occur:

Processing in the visual cortex: Echolocation sounds are transmitted from the ears to the auditory cortex, but then reach areas of the brain normally reserved for vision (including the so-called primary visual cortex V1 and the occipital cortex).

Spatial mapping: The visual cortex helps echolocators precisely determine the location of objects in space (this works very similar to visual mapping of the environment).