Auditory illusions and their use in a composition as a compositional element (topic of research)
The aim of my research is mapping and consecutive use of potential of distorted perception during analysis of concrete musical effects, which will be subsequently applied as compositional elements of a composition. Distortion of our perception can be for example caused by “false” evaluation of a specific sound stimulus through our sensual brain receptors or non-linearities which originate within framework of transfer function of human organ of hearing. I will try to use this fact diversely and subsequently it project into compositional thinking thanks to which we enlarge space for perception of musical process in our space-time for other possibilities. For example, from the point of view of perception of structure, time, timbre, organisation and ratio of pitches, manipulation with registries or subjective switching between roles of singular layers. One of the intentions is to support premise that auditory illusion can be an adequate compositional element within the structure of musical space like any other sound exposure whether in the form of melodical ornaments, multifonic or other enlarged widespread techniques or compositional approaches.
The mentioned musical effects(phenomena)which are subject of psychoacoustic research for acousticians, musicians (composers and theoreticians), cognitive psychologists and neurologists, are in general meaning auditory illusions. Here I understand expression illusion as distortion of reality which happens by acceptance of certain type of sound stimulus by human ear, when our ear and brain which process sound into sensations, change relations between physical components which existed during creation of the stimulus. The sensations which appeared do not in fact really exist (whether it concerns auditory, space or optical illusion the basic principal is the same).
Basis for origin of auditory illusion is a real sound stimulus, specific characteristic of which, in acoustic sense (time, spectral, general level of acoustic pressure etc.), were objectively given by structural and excited properties of used sound sources and their time-space proportions, can be cause of distorted and often also changeable process of our perception. E.g.: There is given a kind of specific music formation or rhythmic sequence in musical notation within the score (objective reality) and subsequently interpreted in this way. In case of auditory illusion, when such a music section is perceived by a listener with his “not perfect sensory processes”, there originates here incongruity (discord) between musical notation and that, which music patterns, rhythmic layers or formations our perception evaluated as so-called right (subjective reality). Results of psychoacoustic tests often tell us about existence of different possibilities or combinations of how similarly, same way or differently we can perceive one and the same section.
Subject of my study are specifically multistable or bistable auditory illusions. Within framework of one emitted stimulus we are able quite independently on ourselves to hear several of its forms (bistability-max.2 forms, multistability-3 and more different forms). Individual forms are possible to be heard only
separately, this means that our perception unpredictably switches over between them, just as, for example, between two pictures in case of bistable optical illusion. So we never perceive more in one go. There could be a question for composers, by which means it is possible to influence these unpredictable forms and subsequently create from them musical space? Which way to use for this purpose e.g. spectrum of acoustic intruments, influence of amplitude in time, tempo plus rhythm, subjective versus objective perception of music flow(layers) in time. Another question which fluently follows the previous ideas is the range of influence of different kinds of auditory illusions on tectonic and formal side of composition.