Non-speech Audio-semiotics a Review and Revision of Auditory Icon and Earcon Theory

The aim of this paper is to develop a theory and taxonomy of auditory signs, based on semiotics. For more than two decades, the discourse on non-speech audio interfaces has been dominated by a dichotomy between auditory icons, which are based on everyday hearing, and earcons, which are based on musical hearing. The corresponding theory behind these concepts has to be revised for several reasons. First, the authors of these theories partly use semiotic concepts and terminology, but not always in a correct way. Second, the classification of auditory icons as "iconic", and earcons as "abstract" is too simple and based on the questionable premise that everyday sounds are per se iconic and musical motives are per se abstract and symbolic. Third, this widespread idea ignores the crucial role of the user in the process of perception. In addition, the users' perception of visual and auditory signs in computer interfaces is fundamentally different today, from how it was in the early years of graphical user interfaces — the time when the first auditory interfaces and the corresponding theories were developed.