The protagonist in Parker's 13th novel has synesthesia, a condition that is believed to effect about 1 in every 200 people with a bias towards left-handed women.
Synesthesia comes from the two Greek words syn (together) and aisthesis (perception) - therefore synesthesia literally means "joined perception".
A synesthete experiences one sense with another. For example, on hearing a particular piece of music he/she might taste a particular flavor.
The most common form of synesthesia appears to be when someone sees a letter, number or word as a particular color - for example a synesthete might see the word car as sky blue and the number 5 as light green. Almost any combination of the senses is possible - there are synesthetes who experience sound in response to smell, others who experience smell in response to touch, and occasional incidents where three or more senses are involved.
As I understand it, the synesthete experiences these cross-sensory perceptions in a very ...