Have you ever heard colours and/or seen sounds?

Yes. I have to stress that the feelings that accompanied this effect were extremely intense. I often felt like i was on a roller coaster, or flying through space. I had difficulty distinguishing one of my senses from the next, including tactile, taste, everything. The tactile sensations were extreme; I felt like invisible parts of my body extended out into dimensions I could never have seen before; I could look at something and feel it as a part of me.
LSD is incredible.

Nope, but some people can't help it. It's called synesthesia, and it's a mild sensory disorder in which the brain consistently confuses certain sensory signals. Many people who have it can "taste" words or colors, and there are actually many similar forms of synesthesia, like the perception of tones as colors, or seeing certain words in very specific colors.

This is possible when using acid or shrooms. your senses get mixed up, can't really explain it. but you do see sounds and hear colors. cool experience.

Ah, synaeshtesia. Yes! I see certain sounds (word-forms and syllables) as colour. I remember people's names by remembering what colour they are. When I was a kid I had an alphabet book that made me angry because they used the wrong colours for the letters.

It doesn't work the other way round, I don't hear colours.

And no, I've never taken LSD or any other hallucinogen.

I have, actually on one of my first LSD trips, and many ones after. It's really an amazing experience, because basically all your senses are connected completly.

No, I have read that it has to do with how we are wired inside. I don't have that characteristic.

Of course. Artists use bright, warm colors for sound, like the painting "The Scream". Those vibrating reds, yellows, and oranges are SCREAMING!!!! I hear them loud and clear.

As for music, you can see the blues when you hear them....and they are pretty blue.

I think a person could actually write a book with more examples.

I tasted music. Does that count? Weirdest of the lot though was a tap dripping into the sink and each time a drip landed it exploded into rainbow colours. Kept me mesmerised for hours. Loved that acid when I was an irresponsible teenager. (This was in the 70s.)

indeeeed :D

Never heard colors, music does seem to create waves that you think you are seeing, or hell you might be for that matter. Wallpaper with owls on it can be fun, they start moving, Had one friend cover her face with her hands and say "you can't see me" and some of my other friends swear they couldn't. I don't advocate drug use, especially in kids, this was when I was a stupid younger man.+4

I have never heard colors but I have seen music waves coming out of speakers. Music is wonderful on hallucinogens. It seems to paint a picture as it flows through the air.

Yes.

nyet.