  In this study, the notion of perceptual features is introduced for describing
general music properties based on human perception. This is an attempt at
rethinking the concept of features, in order to understand the underlying human
perception mechanisms. Instead of using concepts from music theory such as
tones, pitches, and chords, a set of nine features describing overall
properties of the music was selected. They were chosen from qualitative
measures used in psychology studies and motivated from an ecological approach.
The selected perceptual features were rated in two listening experiments using
two different data sets. They were modeled both from symbolic (MIDI) and audio
data using different sets of computational features. Ratings of emotional
expression were predicted using the perceptual features. The results indicate
that (1) at least some of the perceptual features are reliable estimates; (2)
emotion ratings could be predicted by a small combination of perceptual
features with an explained variance up to 90%; (3) the perceptual features
could only to a limited extent be modeled using existing audio features. The
results also clearly indicated that a small number of dedicated features were
superior to a 'brute force' model using a large number of general audio
features.
