cERTAIN SOUNDS HAVE SHAPES AND MOVEMENTS, IS THIS synesthesia OR AM i JUST A CRAZY PERSON?

I'm just wondering it this is what it is as somebody mentioned synesthesia to me recently when I was talking about this. When I hear certain sounds I see shapes in my head and I can also feel those shapes while listening to the sound. They mostly show up as different kinds of bending lines, the lines then will move in different ways and when they do I feel it in my body, I almost want to move with them. It's mostly only in vocal tones though, I tend not to experience these with instrumental music.