I am sooo glad I read this as I'm on the verge of quitting my job every day due those horrific eating noises. Didn't used to bother me massively, but over the last 6 months it's got really bad to the point that I'm like Llamatron and go from placid to extreme rage in seconds.
It got really bad one day last week when the person involved ate a Mars Bar in the morning, then sandwiches with garlic (in a small office!) noisily and then another sandwich later on. And since it can take them half an hour to do this, there's only so much time I can escape from the office.
I also hate being left in the office on my own incase the phone rings. Nothing against it ringing, but due to a hearing problem, it's much harder to pickup what people are saying. This has now turned into a kindof paranoia about the phone although I'm slowly getting better.