The Perception of Musical Consonance

This report, while reviewing the subject, tries to determine which factors are involved in the decision of the Central Nervous System (CNS) to perceive as either consonant or dissonant (pleasant or unpleasant) a given combination of sounds. Interest in the subject appears demonstrated by the enormous number of papers dealing with it from different viewpoints. Willingness to understand the complex neurophysiological mechanisms is a strong driving force along with more pragmatic avenues, such as the development of predictive models to better deal with auditory pathologies, the use of music as alternative therapy, or the design of new instruments or even new scales. Herein, the critical bandwidth CB and double critical bandwidth 2CB concepts are discussed in relation to psychoacoustic consonance and dissonance and under the light, too, of recent non-linear models of pitch perception, along with their possible role in that intriguing mechanism. Besides, the role of the auditory periphery, the contributions of the central nervous system (CNS), hormonal factors and cultural components, are also considered. As a novel concept in this field, we put forward herein the non-linear dynamic approach, which explains musical consonance in very simple terms: The sensation of consonance is assigned to a well defined parameter, that is, the stability of the so generated dynamic attractor. However, it is concluded that the subject is far from being understood and still requires deep study and thought, both from biophysical and psychological frameworks.