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 It should function as a historical reference book.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.

Synesthesia is a rare kind of perception in which sensory input or cognitive concepts, such as units of measurement or the alphabet, automatically lead to additional sensations. The most common characteristic is grapheme-color synesthesia, followed by sound-color synesthesia. The prevalence of people with synesthesia is about 4%. Every synesthesia remains constant throughout the lifespan. Research on synesthesia gives insight into individual differences of perceptions and experiences of healthy people. In this project, work was done on mainly four main sub-projects: 1. Synesthesia research during the 19th century. The evaluated literature in three extensive historical articles goes far beyond the previously known bibliographies on the topic. Many ideas recently 'discovered' by science can be traced back to the 19th century, for example a starting discussion about a distinction between synesthesia and crossmodal correspondences; the integration of new subforms into the concept of synesthesia, such as tickertape synesthesia, or sequence personality synesthesia; different kinds of spacial locations of synesthesia. 2. Timbre-color mappings. In empirical studies the dependency of the synesthetically perceived colors from pitch, timbre, partials, as well as, from transforming the sound from one instrumental timbre to another has been investigated. Furthermore, a new research field has been opened: Timbre-color mappings in an intercultural comparison, presented with participants from Madagascar. These studies give new insights in perception of timbres, as well as, in the still unclear relation between synesthesia and crossmodal correspondences. In historical studies, the history of timbre-color mappings in non-synesthetes, starting in the 17th century, was rediscovered, as well as, the history of timbre-color mappings in synesthetes in the 19th century. 3. Synesthesia research in Russia. The Russian research on synesthesia and intermodality in the context of music, as documented in the Kazan Congress Reports 1967-2015, was recorded for the first time. This bibliography with 1212 titles is intended to give a starting point for an evaluation of Russian research in the West. Additional, an English translation of two Russian anthologies on synesthesia and synthesis of the arts was published in the West. This is of value to us today as it helps to explain the different 'East' and the 'West' concepts of synesthesia and crossmodal correspondences and to learn from each other. 4. International conference 'Music and synesthesia', Vienna, July 3-5, 2020. The congress had to be cancelled due to the Covid-19 pandemic. The conference proceedings with abstracts from 25 oral and 20 poster presentations from 17 countries from Europe, North and South America and Australia were published.