The History of Colored Hearing from 1812 until 1988

Synesthesia is a rare kind of perception in which sensory input or cognitive concepts, such as music, days of the week or the alphabet, lead automatically to additional sensations. These are experienced simultaneously with the trigger, meaning that the trigger and sensations are inseparable. For example, words trigger a taste at the same time, letters acquire textures; sounds, numbers or weekdays are felt as colored. Nowadays, at least 73 types of synesthesia are known, all having to do with a constant and involuntary linking of sensations. This
condition can be found in at least 4% of the population, and it has its advantages mostly in dealing with everyday tasks (e.g. memory performance). Research on synesthesia gives insight into individual differences of perceptions and experiences of healthy people, and helps to understand how different brains can perceive reality differently. One of the most frequent sub-forms of synesthesia is colored hearing, the perception of colors and shapes along with auditory stimuli, mostly while listening to tones, sounds or music.
The first documented case of a synesthete is from 1812. Since then, a lot of cases have been described, and empirical studies have been conducted. During the 19th and 20th centuries, an intensive discussion took place, which has not yet been resolved. There is neither a comprehensive international bibliography on the history of colored hearing through 1989 nor a collection or critical view of the results. Therefore, as a contribution to the history of science, the goal of this project is to bring together the enormous stock of literature from different
languages for the first time and to compile as far as possible a complete bibliography. This will then be evaluated with regard to the evolution of hypotheses and theories on colored hearing.
The evaluation will be published in English as an extensive monograph, with a translation of all important sources and a detailed index. It should function as a historical reference book. Additionally, an online database (open access) will be provided with as many details as possible on colored hearing. Thus, we will be able to preserve the knowledge of colored hearing from the 19th and 20th centuries. Up until today, a lot of sources have not been available via the internet, nor can they be found in common bibliographies, such as Medline or Psyndex.
The project will be completed with an empirical study (in cooperation with the synesthesia lab in Brighton, U.K.), a strong collaboration with the International Association for Synaesthetes, Artists and Scientist (IASAS), and an international congress on colored hearing (in Vienna). These measures will create new perspectives and make the Institute for Musicology in Vienna an international central point of contact for synesthesia.