Disclosed is a method and apparatus for processing an audio signal based on an extent sound source. The method includes identifying information on a reference area of the extent sound source and information on a position of a listener, determining a position of a virtual sound source within the extent sound source based on a relationship between the position of the listener and the reference area of the extent sound source, and rendering an audio signal based on the determined position of the virtual sound source, wherein the reference area may be determined based on a position and a size of the extent sound source.