CHROMESTHESIA
Chromesthesia (a form of synesthesia) is neurological phenomenon in which heard sounds automatically and involuntarily evoke an experience of colors, forms, or shapes. Voice, music, and assorted environmental sounds trigger color and firework-like shapes that arise, move around, and fade when the sounds end.
Individuals rarely agree on what color a given sound is. B flat might be orange for one person and blue for another. For some, music produces waving lines like oscilloscope configurations—lines moving in color, often metallic with height, width and, most importantly, depth. Synesthetes also perceive colors and forms in different ways. Projectors perceive color as occurring in the external space, on a screen in front of their faces, whereas the associates perceive colors in the mind of their eyes. These two terms are however limiting since they do not express the real nature of the experience.