An audio signal processing apparatus including an index estimation unit that receives three-dimensional image information as an input and generates index information for applying a three-dimensional effect to an audio object in at least one direction of right, left, up, down, front, and back directions, based on the three-dimensional image information; and a rendering unit for applying a three-dimensional effect to the audio object in at least one direction of right, left, up, down, front, and back directions, based on the index information.