Measurement of the beauty of periodic noises
  In this article indicators to describe the "beauty" of noises are proposed. Rhythmic, tonal and harmonic suavity are introduced. They give a characterization of a noise in terms of rhythmic regularity (rhythmic suavity), of auditory pleasure of the "chords" constituting the signal (tonal suavity) and of the transition between the chords (harmonic suavity). These indicators have been developed for periodic noises typically issued from rotating machines such as engines, compressors... and are now used by our industrial customers since two years. 
Vincent Manet
physics.class-ph