Entropy, pitch, and noise: organisation and disorganisation in the perception of closure for different types of spectra

In this article, we develop a hypothesis on the role of spectral entropy in conveying a sensation of termination for short musical fragments. We tested the hypothesis in an experiment presenting spectral sequences involving sounds categorised in three families (pitch, bell, or noise) and asked 64 participants to rate their levels of closure in a Likert scale with five degrees. The results highlight an agreement by all participants to consider stimuli transiting from organised (e.g. pitch) to disorganised spectra (e.g. bells, noise) as more complete than transitions from the opposite direction.