A method of processing an audio input signal represented as digital samples to produce a stereo output signal (having a left field and a right field) such that said stereo signal emulates the production of said audio signal from a specified audio source location relative to a listening source location. An audio input signal is received. An indication of an audio source location relative to a listening source location (an indicated location) is received. A broadband response file for each of the left field and the right field is selected from a plurality of stored files derived from empirical testing, dependant upon said indicated location. The audio input signal is convolved with each of the selected left field response file and the selected right field response file. Apparatus for processing an audio input signal.