Sound decomposed into sines, transients and noise with the SiTraNo app

Researchers of the Aalto Acoustics Lab have been looking for better ways to decompose sound into its three basic components: sines, transients and noise (STN decomposition). Leonardo Fierro demonstrates how the “SiTraNo” app can be used to break sound into its atoms – in this case himself rapping. Based on the ideas of auditory perception, fuzzy logic, and perfect reconstruction, Leonardo optimized the way sound is decomposed. For this, he used a genetic algorithm, which simulates the survival of the fittest. In the enhanced method, sines and transients are two opposite characteristics of sound, and the sound is not allowed to belong to both classes at the same time. However, any of two opposite component types can still occur simultaneously with noise. Thus, the idea of fuzzy logic is still present, although in a restricted way. The noise works as a fuzzy link between the sines and transients, describing all the nuances of the sound that are not captured by simple clicks and whistles. “It’s like finding the missing piece of a puzzle to connect those two parts that did not fit together before”, Leonardo says. Read more: https://www.aalto.fi/en/news/acoustics-researchers-decompose-sound-accurately-into-its-three-basic-components