Evaluation of HE-ACC, AC-3, and E-AC-3 codecs

The Recording Arts Program at the University of Colorado at Denver and Health Sciences Center (UCDHSC) performed an independent evaluation of three audio codecs: Dolby Digital (AC-3 at 384 kbps), Advanced Audio Coding Plus (HE-AAC at 160 kbps), and Dolby Digital Plus (E-AC-3 at 224 and 200 kbps). UCDHSC performed double-blind listening tests during the summer of 2006, which largely adhered to the standards of ITU-R BS. 1116-1 (which provides guidelines for multichannel critical listening tests). The results of this test illustrate a clear delineation between the AC-3 codec and the others tested. Test procedures and findings are presented.