Ok, it sounds like it's not as abnormal as it seems, since people seem to understand where he is coming from. I can too, to a certain extent. If I'm trying to read something complicated and Dh is sitting next to me making loud chewing noises, it's really annoying. However, DS seems a bit over the top. I've seen him actually pry DD's mouth open and inspect inside, like the "gum police" to make sure that what she was chewing was not gum.
We did a trial of meds (ritalin) the first few weeks of school and apparently he was having problems with gagging at lunch or saying he was going to throw up and wanting to go to the nurse all the time, which we haven't seen at home. I'm thinking it's a side effect of the meds, or it could be annoyance at the "chewing" going on at the table. We stopped his meds over a week ago and DS says he's not having that issue anymore. The complaining about gum (at school) didn't happen til after we stopped the trial of meds. So maybe when he is not medicated he is over-distracted by certain sounds/images. I think we're going to have to put him on meds again (but try a lower dose), so it should be interesting to see if the gum issue goes away. HIs IEP manager emailed me a long list of abnormal behavior that he's been having since we took him off, that didn't exist before: running down hallways, excessive silliness, lack of focus, perseverating (whatever that is), sticking his tongue out while writing (overflow), etc. etc. etc. Ugh.
