[youtube https://www.youtube.com/watch?v=OQMIWcD7d2c]
2007 Giorgios Kormpakis, video on “Synaesthesia”
Synesthesia (also spelled synæsthesia or synaesthesia; from the Ancient Greek σύν syn, “together”, and αἴσθησις aisthēsis, “sensation“) is a neurological phenomenon in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway.[1][2][3][4] People who report a lifelong history of such experiences are known as synesthetes.