This is called synesthesia. Galton called it synesthesia, a mingling of the senses.

I was curious about this, so it led me to the work of a Danish physicist called Tor Norretranders, and he converted the bandwidth of the senses into computer terms.

Well, again, it's dark out there to human senses. But all you've got to do is take a telescope, even one of present day design, look out and you'll see the same galaxies as we do from here.