"(A)" Brain regions responding to amplitude-modulated acoustic stimulation. "(B)" Brain regions responding to intelligible speech > temporally complex control conditions. Intelligible speech – i.e., amplitude-modulated acoustic stimulation that conveys linguistic information – recruits a broad network of bilateral cortical regions that are organized into parallel hierarchies. Within this network, regions show differential sensitivity to the surface features of speech (i.e., acoustic information), with areas removed from primary auditory cortex primarily responding to the degree of linguistic information in the speech (Davis and Johnsrude, 2003).