XPLMSetAudioPosition

XPLM_API FMOD_RESULT XPLMSetAudioPosition(
                         FMOD_CHANNEL*        fmod_channel,
                         FMOD_VECTOR*         position,
                         FMOD_VECTOR*         velocity);

Move the given audio channel (i.e. a single sound) to a specific location in local co-ordinates. This will set the sound to 3D if it is not already.