Synesthesia is a neurologically based condition in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway. People who report such experiences are known as synesthetes.
So, for example, people may involuntarily experience a colour whenever they see or think of a number. Many people with synesthesia use their experiences to aid in their creative process, and many non-synesthetes have attempted to create works of art that may capture what it is like to experience synesthesia.
http://colourfulanguage.wordpress.com/ is a blog by Lauren who lives in the UK, has synaesthesia, and likes it!
I was recently writing about colour blindness in the context of design and noted that most colour blind people see colour – it’s just they have poor discrimination and some colours look the same to them whereas to a so-called normal observers they would look different.
People who don’t see colour at all are rare. But I was just reading about one, Neil Harbisson, a classically trained pianist who has been colour blind since birth. He suffers from a condition called Achromatopsia which means he can only see the world in grey. However, he has recently being used a piece of technology that allows him to hear variations in colours. The eyeborg helps translate colours into sound and transforms the colour information picked up by the built-in camera into sound frequencies. For example, when he looks at a red, for example, he hears an F (= 349.23Hz); if he sees a yellow he hears a G. For more information see http://www.techeye.net/science/technology-helps-man-hear-colours.
I wonder what this would feel like. Of course, synesthesia sometimes occurs naturally. That is, some people can hear colours, see sounds, taste numbers etc. I sometimes think that Kandinsky (the artist who worked at the Bauhaus) may have been synesthesic because of his interest in the relationship between colour and shape. Quite possibly, sensing the world in a way that is different to how most people perceive it may me an advantage to an artist.