Colour-sound (or colour-tone) synesthesia

This could be considered a type of visual-auditory or conceptual-auditory (concept-sound) synesthesia

This is a rather uncommon, little-known type of synesthesia in which seeing colours triggers sounds, i.e. tones, frequencies or musical notes.

Information on this type of synesthesia is scarce as it appears that no scientific studies have ever been conducted on it. According to reports by the synesthetes who experience it, it seems to be evoked in response to stimuli such as abstract paintings or coloured objects and surfaces (walls or clothing for example). The sounds heard are not usually loud or strident but tend to be more like a low hum, or pure tones at a low volume. The depth and texture of the colour observed can also induce changes in the tone or note heard or perceived.

However, it is also true that some synesthetes with auditory-visual synesthesia (chromesthesia or sound-to-colour, the opposite of the type described here), or even people without this type of synesthesia, can receive sound or music impressions from different colours if they focus on them (see the description below). 

Here are some descriptions written by people with what could be considered true colour-to-sound synesthesia:

“My personal experience [is that] all colors are experienced as a sort of tone. (…) Certain vibrant colors are experienced shrill like an alarm, white reminds me of the hum of electricity.”

(Source: This (since deleted) post on Reddit/Synesthesia. 2021.)

Our second informant tells us that they regularly experience a colour-to-sound effect on observing objects in their home, with the automatic and consistent perceptions typical of synesthesia. Although there are no actual harmonies, they mention different frequencies, and so on observing very varied colour combinations or if the colours form specific curves, shapes etc. this can give the impression of a kind of basic musical composition:

“For me it’s not musical notes. It’s like lighter colors are a higher frequency than dark colors. Like looking at this yellow cup by me sounds like medium to high pitched “mmmmm” or when I look at the brown wall in my room it’s a low heavy almost droning sound.

Sometimes, with art. If it’s an abstract painting with crazy colors it can sound like a song as I’m looking at it. I think that’s a couple different kinds of syn working together though, maybe my motion sound interacting with the color sound.

So say there’s a red line, and it’s wavy in the painting. The sound from the color will “wave” with the line as I’m looking at it. If you’ve ever played guitar hero it’s like the notes that you’d hold and you can wave to change the sound.”

(Source: This comment on Reddit/Synesthesia. 2020.)

The art connection appears again in the case of this next synesthete, who is highly sensitive to interacting colour combinations and, interestingly, clearly hears the sounds physically as if they were really happening. Their experience is also incremented when it has novelty value and consequently makes a stronger impression:

“Some art is difficult because it either doesn't resolve tonally in a way that I can handle, or the tones/notes just do not work together, no matter how hard I try. Some colors will always sound nice with each other, some will only sound okay with another tone to fill out the harmony. (...)

I actually hear the sounds physically. Environments that I am in a lot, I "hear" less, like how you don't notice how your house smells.

There are some works of art that involve color that just don't work for me... I can appreciate the technique, but looking at them is like if you were to listen to two random and adjacent piano keys held down.”

They also experience sound sensations in response to the colour schemes of clothes, fashion and on-stage costumes, and another interesting aspect, coherent with their artistic aptitude, is that they can use their perceptions creatively on dressing to create a look that seems pleasing to the ear:

“Going to see operas or musicals, sometimes the costumes clash drastically with the music of the show, and that can be distracting.”

“And yeah, it does dictate how I dress. I tend to stay within a certain color scheme because I like how it sounds (...) Some days I don't care what I look like and wear what sounds nice to me. (...) When I get kinda dressy to full on fancy, I work it. The ability to build really nice and complex harmonies with my clothes."

(Source: This comment on Reddit/Synesthesia. 2020.)

This post and comments on Reddit/Synesthesia from 2022 also has some very interesting cases of colour-sound synesthesia in response to paintings. 

When sound-to-colour synesthetes experience colour-to-sound impressions

Some synesthetes with auditory-visual synesthesia (chromesthesia or sound-to-colour, the opposite of the type described here) receive sound or music impressions from different colours if they focus on them. These impressions would generally be perceived in their mind rather than them actually physically hearing sounds or music playing, and the specific colour-sound pairings would basically correspond to those of their chromesthesia. This could be considered either a kind of two-way synesthesia, if the effect is strong, or maybe just a deduction of what a colourful scene would sound like if it had sound, aided by their sensitivity as an auditory-visual synesthete. This effect might also occur less spontaneously as a cross-modal correspondence in people who do not have chromesthesia: if asked to do so, they could choose particular sounds or types of music that would sound logical or "right" for certain colours or colour combinations.

In this video, Tree author Pau “sings” an abstract painting by Ninghui Xiong at the 2018 Synesthesia Congress in Spain (the weird singing situation starts at 2.10 min, with a repetition at the end of the video).

The case of Neil Harbisson, the human cyborg

It may not be synesthesia, but it’s a very interesting case that has to do with perceiving colours as tones. The artist Neil Harbisson has a condition called achromatopsia: he has never been able to distinguish colours and sees the world in black and white. After having an antenna that detects the unique light frequency of each different colour implanted in his skull, he receives signals with their corresponding tone frequencies and can actually hear colour. He says his electronic eye has greatly improved his quality of life and considers himself the “first human cyborg”.

Photo: Smart Speakers

This page last updated: 15 May 2026