I can't say I've had this experience. I have had a few instances of synesthesia after smoking changa, though. Is it possible that you heard light raindrops while you were affected? I could understand you feeling that sensation if you could hear it. I don't know for sure though. I've been petting my cat while half way through a breakthrough and began to see fur like distortion in my visual field.
"..dimethylated spirits on fire in me.."