Neil Harbisson was born colour blind and never experienced colour through sight. After a lecture ‘sensory extensions via cybernetics’ in 2003, given by Adam Montandon, the two began to develop the ‘eyeborg’. A head mounted camera reads colour directly in front him and converts it, in real-time, into sound-waves which translated dependent upon sound frequency. High frequency hues are high pitched and low frequency hues, low pitched.
Having never experienced colour Neil states that it wasn’t until he perceived colour instinctively through sound that he began to dream in colour and only then did he feel the eyebrow was an integral extension of his sense.
(for further reading refer to Neil Harbisson’s Wiki page)