By: Hendrik Böhne, René Gröger, David Hammerschmidt, Robin Helm, David Hoga, Julian Kraus, Jakob Rösch, Christian Sussek
This paper aims to assess the audibility of potential quality loss in MP3-compressed files compared to CD quality files (WAV-files), as well as the influence of listening habits on qulatity evaluation. For this study, samples of various musical genres were processed in different MP3 compression rates (48 kbit/s to 256 kbit/s). 21 listeners participated in an A/B comparison task judging random combinations of either CD quality files to compressed files or compressed files among each other. We investigated whether trained listeners notice differences between the files and whether they prefer CD quality or MP3 quality. The results show that each participant notices differences in files compressed at the lowest rate 48 kbit/s. Differences in files at 128 kbit/s and higher cannot be noticed within the majority of listeners. At 96 kbit/s the majority at least notices differences between the MP3 and the WAV-files. Still some subjects judge the MP3 versions as sounding better. Additionally, differences appeared in terms of media use of participants. Subjects who only consume compressed formats were much less able to tell compressed from the uncompressed music than subjects who still listen to uncompressed CDs. So the exclusive use of compressed media seems to lead both, to a decrease in sound perception ability, as well as to a tendency to favour the compressed music over the uncompressed music.