The influence of loudspeaker-listener distance on the detection of low-bitrate audio coding artefacts

This study investigated the influence of loudspeaker-listener distance on the detectability of low-bitrate coding artefacts. Two sets of ABX listening tests were conducted in an ITU-R BS.1116-compliant listening room: (i)headphone reproduction (reference anechoic condition) and (ii) loudspeaker reproduction in the listening room (at 1 m, 2 m and 4 m listening distances). Results from the headphone test for each subject determined the bitrate to be tested for the same subject in the loudspeaker test. Results showed that only the subjects who passed the headphone ABX test at a higher bitrate were affected by listening distance in the loudspeaker test. No clear evidence was found to support the conventional recommendation of minimum 2 m listening distance for the critical listening test.