The phenomenon of seeing colors in response to musical stimuli is called chromesthesia or sound-to-color synesthesia. It is a type of synesthesia, which is a fascinating neurological condition where stimulation of one sense leads to an automatic experience in another sense. People with chromesthesia associate certain colors with certain sounds, music notes, instruments, keys or musical compositions. So when they hear music, they may visualize a complex landscape of colors, shapes, textures and motions in their mind’s eye corresponding to the music. Chromesthesia is an involuntary cross-wiring of the senses that around 1 in 2,000-4,000 people are estimated to have.
What is Synesthesia?
Synesthesia is a perceptual condition in which stimulation of one sensory pathway leads to involuntary experiences in other sensory pathways. It is caused by cross-activation between different sensory modalities or pathways in the brain. Around 4% of people are thought to have some form of synesthesia. There are over 80 different types of synesthesia that have been documented by researchers. Some common forms include:
- Grapheme-color synesthesia – letters or numbers are perceived as having certain colors
- Sound-color synesthesia (chromesthesia) – sounds evoke the visualization of colors
- Number form synesthesia – numbers are visualized with precise locations in space or along complex mental maps
- Lexical-gustatory synesthesia – words or names have distinct taste associations
In synesthesia, the triggering stimulus (e.g. sound) and the sensed additional experience (e.g. color) are automatically and consistently paired. These color perceptions are stable over time. The brain wiring that causes these extra sensory experiences may be present from birth. Synesthesia runs strongly in families and is more common in women. It is not known exactly what causes synesthesia, but it may be linked to increased connectivity between different sensory regions of the brain.
Chromesthesia: Hearing Colors from Music
Chromesthesia is one of the most common and well-known forms of synesthesia. People with chromesthesia automatically and consistently perceive colors in response to sounds and music. While the exact music-to-color perceptions vary between different individuals, there are some common themes:
- High pitched notes tend to be seen as lighter, brighter colors like white, purple or pink
- Lower pitched notes are associated with darker hues like blue, green or red
- Dissonant intervals or chords may elicit brown or gray colors
- Timbre or texture of instruments can map to textures – horn instruments may seem smoother compared to strings
Some individuals see colors streaming directly from musical instruments or the vocals of singers when hearing live music. Others have moving kaleidoscopic visualizations in their mind’s eye corresponding to the melodies, harmonies, rhythms and tones. The music-triggered colors can sometimes take on abstract shapes, patterns, landscapes or scenes rather than being static blotches of color.
While these color perceptions are subjective to each synesthete, sound-color combinations are often consistent across time for a given individual. For example, middle C may always trigger green, while a violin’s sound always induces blue wavy lines. This makes chromesthesia a reliable psychophysical phenomenon despite the idiosyncratic nature of the colors sensed.
Prevalence of Chromesthesia
It is estimated that chromesthesia is present in 1 in 2,000 to 4,000 people in the general population. However, its true prevalence is difficult to ascertain given that many synesthetes may not realize that their music-color perceptions are unusual and never get formally diagnosed.
Some studies have found higher rates of chromesthesia and synesthesia among artists, musicians, writers and other creatives. There may be certain professions like painters, poets, composers where synesthesia is disproportionately represented and actively utilized.
| Study | Sample Group | Prevalence of Chromesthesia |
|---|---|---|
| Cytowic et al 1995 | General population | 1 in 2,000 |
| Simner et al 2006 | General population | 1 in 2,000 |
| Mulvenna & Walsh 2005 | Art students | 1 in 25 |
| Peacock 1988 | Art students | 1 in 10 |
Chromesthesia appears to run strongly in families. If a parent has synesthesia, their child has a 50% chance of inheriting it. The condition may also occur due to changes in chromosome structure. Certain genetic markers have been found in synesthetes including on chromosomes 2q24, 5q33, 6p12 and 12p12.
Neural Basis
In the last couple decades, scientists have started investigating what is happening in the brain to cause synesthesia. Neuroimaging studies show that there are differences in the structure and connectivity of the brains of synesthetes compared to non-synesthetes.
Researchers have found greater neural connectivity in synesthetes between regions involved in color processing (V4) and regions involved in recognizing letters or processing music and sounds. There also appears to be differences in gray matter volume in areas linked to the paired sensations.
Overall, this evidence points to the idea that synesthesia arises from “cross-wiring” between normally distinct sensory regions of the brain. This may be due to incomplete pruning between brain areas during early development.
Experiences Reported by Chromesthetes
Synesthetes report rich, complex and vivid experiences in response to sound and music. They describe seeing splashes, ripples, shapes and textures in a “mental screen” overlaid when listening to music. Some examples of first-hand accounts:
- “When I hear music, I see moving patterns of color. It’s like watching a light show or looking at a kaleidoscope. The colors move and swirl with the melody and tempo in bright, vivid hues.”
- “Different instruments have different colored ‘auras’ around them. Trumpets blaze in an orange aura. String instruments have a blue-green halo.”
- “When I hear minor chords or discordant notes, it looks visually jarring – like brown and gray static.”
Many chromesthetes compare it to seeing a “mental fireworks display” or a abstract painting that unfolds in tune with a musical composition. The visualizations are seamlessly evoked by the sounds.
While these sensory experiences are stimulating, some synesthetes report drawbacks such as visual overstimulation at concerts or difficulty concentrating if there is background noise. Overall though, most synesthetes enjoy their unique perceptions and consider it an asset in their creative endeavors.
Uses in the Arts
Synesthesia has intrigued artists, musicians and poets for centuries. Composers like Franz Liszt, Olivier Messiaen and Alexander Scriabin created musical works attempting to consciously convey color experiences. Poet Arthur Rimbaud spoke of ‘colored vowels.’
Chromesthetes themselves tend to gravitate towards creative fields like visual arts, music, writing, media and design. Contemporary examples include singers Pharrell Williams and Lady Gaga, painter David Hockney, novelist Vladimir Nabokov, and composer Billy Joel.
Synesthetes are able to harness their color visions to inform their creative work. A composer with chromesthesia may ‘see’ the melodic shapes and textures in terms of vivid hues which inspire the musical harmonies. A poet may pick words deliberately to create a visual cascade of colors. A painter can overlay chromatic soundscapes onto the mind’s eye to evoke abstract colors onto canvas.
While not all artists have synesthesia, the condition demonstrates the brain’s astonishing ability to forge perceptual connections between different senses. Chromesthesia represents an unconscious blending of sound and color that captures a deep human yearning for a unity of the senses.
Conclusion
Chromesthesia is a fascinating neurological phenomenon where music and sounds trigger automatic and consistent experiences of colors, shapes and visual textures. Around 1 in 2,000-4,000 people have this form of synesthesia which arises from cross-wiring between auditory and color processing regions of the brain.
The rich visual imagery evoked by chromesthesia can inspire creative expression in arenas like painting, music, writing and design. Although the precise way sounds elicit color visions differs for each synesthete, common patterns are found like lighter hues with high pitches and darker colors with low pitches. Scientists are steadily uncovering the genetic markers and neural correlates of this unique condition.
Chromesthesia provides a window into extraordinary sensory blending in the human mind and creative potential. While synesthetes are born with these traits, it also reminds us of the amazing capacity of our minds to forge new connections between our senses, should we choose to cultivate it. Ultimately, synesthesia reveals the endless potential for sensory and cognitive flexibility that resides within all human minds.
