Abstract

Musical instrument sounds have distinct timbral and emotional characteristics, and when audio processes are applied to them their timbral and emotional characteristics are changed. This paper investigates the effects of MP3 compression on the emotional characteristics of eight sustained instrument sounds using a listening test. We compared the compressed sounds pairwise over ten emotional categories at several bit rates. The results showed that MP3 compression strengthened neutral and negative emotional characteristics such as Mysterious, Shy, Scary, and Sad; and weakened positive emotional characteristics such as Happy, Heroic, Romantic, Comic, and Calm. Interestingly, Angry was relatively unaffected by MP3 compression. Probably, the background “growl” artifacts added by MP3 compression decreased positive emotional characteristics and increased negative characteristics such as Mysterious and Scary. For instruments, MP3 compression effected some instruments more and others less. The trumpet was the most effected and the horn by far the least.