What Hi-Fi? reports that a new study by the Audio Engineering Society finds MP3s and similar low-quality-compression formats have a distinct effect on the timbral and emotional characteristics of the instruments involved — i.e., strengthening neutral and negative emotional characteristics, and weakening positive ones.
The AES study, The Effects of MP3 Compression on Perceived Emotional Characteristics in Musical Instruments, analyzed compressed and uncompressed music samples at several bit rates over 10 emotional categories.
The study found MP3 compression strengthened emotional characteristics like mysterious, shy, scary, and sad, but weakened positive ones like happy, heroic, romantic, comic, and calm. So, playing Pharrell’s ever-ubiquitous “Happy” won’t have quite the same uplifting effect at a lower bit rate.
Interestingly, the emotional characteristic of anger was relatively unaffected by MP3 compression. The Audio Engineering Society put this down to the background artifacts in such a low-quality compression which could sound like a growl (so take note, death metal fans).
The trumpet was the instrument most affected by the level of compression, the study said, while the horn was the least affected. As the authors note in the study’s conclusion, “The current study also helps provide the basis for content-based refinements of audio codecs in the future. As an example, if we know that the trumpet is particularly changed in emotional characteristics by compression at 32 Kbps, if we have a piece by Miles Davis with a prominent trumpet throughout, we may decide to use a higher bit rate to encode it. Or, future research may indicate how the trumpet could be compressed at 32 Kbps without substantially changing its emotional characteristics.”
The HRAC takeway: Looks like we need more hi-res Miles music in our future to keep ourselves smiling and satiated. Rebirth of the hi-res cool…