1. A method of generating a multi-channel audio signal, the method comprising: representing locations of a plurality of speakers as a plurality of polygons whose vertices are at locations corresponding to the locations of the plurality of speakers; acquiring a location of an object sound; calculating, by way of a hardware-based processor, distances between the plurality of polygons and the acquired location of the object sound; selecting one of the plurality of polygons on the basis of the calculated distances; and generating a multi-channel audio signal that corresponds to speakers corresponding to the selected polygon by mapping the object sound to the speakers corresponding to the selected polygon.