I really experienced this back in 2003 when I had a long attack. My Border Collie and I both started shutting down at a family picnic at the same time--too much noise and too much motion. We both had to leave the area.

It still happens now, but it's more that I can't focus on things when there's noise. I don't get so overloaded as I did before. But sometimes I still have to get away from noise because it is overwhelming. I used to like reading with music in the background, but I can't do it unless it's the music that I used to study to in school. Otherwise it distracts me way too much and I lose my place, have to read things over again because it interferes with my concentration, and in general drives me up a wall. Ugh...

Hope you find a way to deal with it. It's not a fun symptom.