Method and apparatus for two channels of sound having directional cues

A method for generating two channels of sound signals from a multiplicity of sound signals, said multiplicity of sound signals comprising a first plurality of front signals and second plurality of rear signals, said method comprising the steps of:

• applying a 90.degree. phase shift to the second plurality of rear sound signals;
• applying head related transfer functions to the phase shifted second plurality of rear sound signals to generate modified rear sound signals, said modified rear signals comprising signals identified as corresponding to the first channel and signals corresponding to the second channel;
• said front signals comprising signals identified as corresponding to the first channel and signals corresponding to the second channel;
• combining the signals corresponding to the first channel to generate a first combined signal, the modified rear signals corresponding to the first channel being subtracted from the remaining signals corresponding to the first channel;
• combining the signals corresponding to the second channel to generate a second combined signal;
• and recording the first combined signal and second combined signal.

A method for generating two channels of sound signals from a multiplicity of sound signals, said multiplicity of sound signals comprising a first plurality of front signals and second plurality of rear signal, said method comprising the steps of:

• applying a 90 degree phase shift to the second plurality of rear sound signals to generate phase shifted rear sound signals;
• applying head related transfer functions to the phase shifted rear sound signals to generate modified rear sound signals, said modified rear signals comprising signals identified as corresponding to the first channel and signals corresponding to the second channel;
• selectively inverting modified rear signals such the modified rear signals corresponding to the first channel are inverted;
• said front signals comprising signals identified as corresponding to the first channel and signals corresponding to the second channel;
• combining the signals corresponding to the first channel to generate a first combined signal;
• combining the signals corresponding to the second channel to generate a second combined signal;
• and further comprising the step of applying additional spatial cues to the selected ones of the first plurality of front sound signals to generate spatial cued selected front signals, said spatial cued selected front signals comprising signals identified as corresponding to a first channel and signals corresponding to a second channel and respectively recording the first combined signal and second combined signal on a first audio track and second audio track of a film media.

A method for generating surround sound signals comprising the steps of:

• accessing a first channel and second channel of encoded sound signals stored on media, said sound signals encoded by processing a first plurality of front signals and second plurality or rear signals by applying a 90 degree phase shift to the second plurality of rear sound signals, applying head related transfer functions to the phase shifted second plurality of rear sound signals to generate modified rear sound signals, said modified rear signals comprising signals identified as corresponding to the first channel and signals corresponding to the second channel, said front signals comprising signals corresponding to the first channel and signals corresponding to the second channel, combining the signals corresponding to the first channel to generate a first combined signal that is stored as the first channel on the media, wherein the modified rear signals are subtracted from the remaining signals corresponding to the first channel, and combining the signals corresponding to the second channel to generate a second combined signal that is stored as the second channel on the media;
• inputting the first channel of encoded sound signals retrieved to a first channel input to a surround sound decoder;
• inputting the second channel of encoded sound signals retrieved to a second channel input to the surround sound decoder;
• said surround sound decoder decoding the encoded sound signals input and generating a multiplicity of surround sound signals.