I find that a lot more plausible as a primary cause. I've had a lot of that sort of misophonia, and ended up doing a kind of trauma therapy over childhood incid

I find that a lot more plausible as a primary cause. I've had a lot of that sort of misophonia, and ended up doing a kind of trauma therapy over childhood incidents including a situation where my Dad raged at me at the dinner table, parodying my mouth noises (presumably he, too, had misophonia) Turned out, there was more going on in that situation than it seemed at face value. Revisiting the events with an adult capacity to look at context, suggested that my Mom and Dad were having a fight already and repressing it, and that I'd got in the middle. The total lack of context made it seem like the end of the world, and I'd call that a real specific trained aversive reaction if anything could be. If this mouth-brain link exacerbates the problem, I wouldn't be terribly surprised, but I don't think that alone can cause it.