Abstract: A method includes receiving a multi-channel audio signal (101) including multiple input audio channels (102, 104, 106, 108) that are configured to play audio from multiple respective locations relative to a listener. One or more spectral components that undergo a panning effect (1001, 1002, 1003) are identified in the multi-channel audio signal among at least some of the input audio channels. One or more virtual channels (1100, 1200, 1300) are generated, which together with the input audio channels form an extended set (111) of audio channels that retain the identified panning effect. A reduced set (222) of output audio signals, fewer in number than the input audio signals, is generated from the extended set, including recreating the panning effect in the output audio signals. The reduced set of output audio signals is outputted to a user.

Abstract: A method for synthesizing sound includes receiving one or more first inputs (80), each including a respective monaural audio track (82). One or more second inputs are received, indicating respective three-dimensional (3D) source locations having azimuth and elevation coordinates to be associated with the first inputs. Each of the first inputs is assigned respective left and right filter responses based on filter response functions that depend upon the azimuth and elevation coordinates of the respective 3D source locations. Left and right stereo output signals (94) are synthesized by applying the respective left and right filter responses to the first inputs.