The role of loudness in detection of surprising events in music recordings

Abstract

The abrupt change of loudness is a salient event that is not always expected by a music listener. Therefore loudness is an important cue when seeking for events in a music stream that could violate human expectations. The concept of expectation and surprise in music has become recently the subject of extensive research, however mostly using symbolic data. The aim of this work is to investigate the circumstances when a change of sound intensity could be surprising for a listener. Then, using this knowledge, we aim to build a computational model that analyzes an audio stream and points to potential violations of human expectation. In order to check the quality of human prediction, an online (web-based) experiment, based on a gambling paradigm, has been performed. The subjects, after listening to an excerpt from real recordings of classical music, were asked to bet on how loud would be the next continuing seconds. . The results of the survey have shown that the moments of sudden changes of intensity more likely caused mispredictions, however it is obvious that the loudness itself is not the only factor that determines human expectations.