Planum temporale is the area of the temporal cortex that for most people is larger in the left hemisphere than in the right hemisphere; an area in the temporal lobe known to be related to language functioning. Planum temporale is the region of the posterior surface of the temporal lobes between the Heschl's gyrus and the Sylvian fissure. The Planum temporale of the left hemisphere is involved in mediating phonologic processing and language comprehension.