This invention addresses sound recording and mixing methods for 3-D audio
rendering of multiple sound sources over headphones or loudspeaker
playback systems. Economical techniques are provided, whereby directional
panning and mixing of sounds are performed in a multi-channel encoding
format which preserves interaural time difference information and does
not contain head-related spectral information. Decoders are provided for
converting the multi-channel encoded signal into signals for playback
over headphones or various loudspeaker arrangements. These decoders
ensure faithful reproduction of directional auditory information at the
eardrums of the listener and can be adapted to the number and geometrical
layout of the loudspeakers and the individual characteristics of the
listener. A particular multi-channel encoding format is disclosed, which,
in addition to the above advantages, is associated with a practical
microphone technique for producing 3-D audio recordings compliant with
the decoders described.