What do people with synaesthasia experience while watching the iTunes visualizer?

Like, can they “see” things in the vizualizer colors and patterns that ordinary people can’t see? (Like how we can ordinary people see things that colorblind people can see?)

Have there been any psychological studies about this?

And, most importantly, what do the studies—should they exist—suggest about the possibility that the machines are taking us over through our technological creations?