1. An electronic device, comprising: a receiver configured to receive a stereoscopic moving image including a plurality of frames; a controller configured to obtain a change in depth information of at least one object included in the stereoscopic moving image and to produce a sound zooming factor reflecting the obtained change in depth information; and an audio processor configured to apply the produced sound zooming factor to a sound signal corresponding to at least one speaker of a plurality of speakers outputting sound signals for the stereoscopic moving image.