Everywhere we go we are surrounded by colours. Any kind of advertisement is using colours to influence the mood of people. But some people see colours among letters and numbers naturally. People who have Synesthesia.


Based on the greek words "syn" and "aesthesia", which means "joined senses", synesthesia is a rare, neurological condition, where one trigger involuntarily evokes a cross talk reaction not just in one area of the brain, but two or more. Depending on which one of the brain areas is affected, some people smell words, taste touches or see colours when looking at numbers.


Although it has been made a disorder by nazi regime in early 1930, synesthesia is not a disorder. It is a trait, like having green eyes or freckles and it is inherited by our parents. It is estimated that 1 among 23 people (appr. 4-7 % of human population) has at least one of the 63 known types of synesthesia. It is entirely unique to each person individual and always involuntarily. It often comes along with being highly sensitive. Studies also show a high prevalence of synesthesia among creatives.


The interest in synesthesia has been increased during the last years, also because the phenomenon of the joined senses gives a unique insight into our not yet fully discovered brain. Neurologists, psychologists, writers and artists from all over the world started a dialog and are constantly working on de-mystifiying that unique trait.


Learn more about the different types of synesthesia.

Famous synesthetes (selection)

1. Tori Amos, singer, pianist: music--> colour

2. Leonard Bernstein, composer, conductor: timbre --> colour

3. Hélène Grimaud, pianist: grapheme, music--> colour

4. Stephanie Morgenstern, writer: grapheme, music --> colour

5. Vladimir Nabokov, writer: grapheme --> colour

6. Geoffrey Rush, actor: multiple synesthesiae

7. Lady Gaga, singer: music--> colour

8. Pharell Williams, singer: music--> colour

9. Hans Zimmer, composer: music --> colour


Click here for getting a detailed overview about people with synesthesia.


With Cytowic/Eagleman et al. five common types of synesthesia have been elaborated so far:

  1. Spatial sequence synesthesia: The coupling of colour, perspective and spatial configuration with concepts involving sequence or ordinality e.g. number forms (weekdays, months, dates)  are seen in loops around the body
  2. Colour grapheme synesthesia: letters and numbers appear in colour 
  3. Lexical gustatory synesthesia: words and phonemes elicit taste
  4. Coloured hearing: music, sound, noise evoke colours, shapes and movement
  5. Personified graphemes: letters, numbers or punctation "carry" personalities

 For more types see here.

"The song appears as light filament once I have cracked it. As long as I´ve been doing this, which is more than thirty-five years, I´ve never seen a duplicated structure. I´ve never seen the same light creature in my life. Obviously similar chord progressions follow similar light patterns, but try to imagine the best kaleidoscope ever."

(Tori Amos about music, from: Powers/Amos (2005), Piece by Piece)

Coloured hearing


One of the most common types of synesthesia is, when the colour area of the brain (V4 area) is affected. That type is called coloured hearing and is one of the most intense types. Music and sound involuntarily evoke colours, often combined with shapes, textures and movement.  And there are prominent representatives among synesthetes today: Pharrell Williams describes his song Happy as "yellow, with accents of mustard and sherbet orange", and Lady Gaga is describing her song Poker Face as "wall of yellow"


Apart from the colours, which partly seem to be beyond any spectrum at all, it´s Heinrich Klüvers form constants that can be used to help to describe what shapes and movements can be seen through a synesthete inner eye when listening to music. In 1926 Klüver demystified the secret of human visual perception during a ground breaking experiment. He took reports about visual effects produced by a drug and categorized these effects into 4 main categories: (I) tunnels, (II) spirals, (III) lattices, (IV) cobwebs. Klüvers work was later extended, effects like scintillation and extrusion, rotation, grids, central radiation, waves have been added. All reported effects seem to have similar structure.


But still, trying to describe what he actually and simultaneously sees when listening to a piece of music can make a synesthete quickly running out of words.

Coloured hearing is a constant changing, never-ending dream, or to put it with Amos´words:




For more information visit KALEIDOSCOPE MUSIC.