Number-sound synesthesia

A subtype of grapheme-sound synesthesia

Number-sound is a very uncommon type of synesthesia, despite often being cited as an example in general articles in magazines and websites that frequently begin with statements like “Do you smell colours or hear numbers? If you can, you have synesthesia!” Such statements are certainly attractive and suggestive but they are never backed up by interviews with anyone with these types of synesthesia or descriptions of real cases as they are actually very difficult to find.

 

I have discovered that in the few cases where number-sound synesthesia occurs it is normally accompanied by other concurrents at the same time, which could be gustatory, olfactory or colour-related, and so concentrating on a particular number could create a minor explosion of taste, smell and colour while a frequency, musical note or other specific sound is heard as part of the same perception.

Here are some descriptions written by people with this type of synesthesia:

“For me, some numbers have sounds, temperatures, personalities, textures, flavors, or colors. For instance, 16 has a high pitch like a small chime, and tastes like frosting.”

(Source: this comment in the blog The Used Life.)

" I hear numbers, equations and generally anything “mathematical”— including pure maths. (…)

Numbers sound bland on their own, bar a special few. By this I mean 1, 3, any number that isn’t “special” in my head. Most integers.

Pi sounds high pitched and almost like a flute? I’d say a high A note. It can be almost painful. It also kind of “quivers” every few seconds. It’s green in my head, but when I’m using it in equations it swirls turquoise and with bits of lilac. It can change forms in “unique” equations, sometimes turning dark grey or pale pink.

Infinity is low pitched, it sounds a bit like a whale and it’s a G note. (…)

Zero is (...) a middle C or D. Some quivers, but mostly bland and “flat”. Zero’s sound is really variable based on the equation and context. My brain doesn’t associate with the symbol, more so the meaning behind the symbol, which varies a lot based on the equation.

Negative numbers are higher-pitched than positive numbers, for the most part. They’re not equal but opposite soundwise. (...) Absolute function graphs sound beautiful. (…)

There’s nothing more satisfying when an annoying high-pitched, staticy equation jumps into a beautiful melody.”

(Source: This comment on Reddit/Synesthesia. 2019.)

Related synesthesia types:

Grapheme-sound (with an example of letter-sound)