British-Irish Neil Harbisson posed with his antenna in Mataro near Barcelona, Spain on September 23, 2021. /CFP

Known as the world's first cyborg artist and a transpecies activist, Harbisson implanted and osseointegrated an antenna, a sensory system, in his skull. /CFP

The system allowed him to hear the colors as audible vibrations inside his head, including invisible colors and those from other sensors or satellites. /CFP

Since 2004, the antenna has been permanently attached to the artist's head. /CFP