Ack. I get that. Sometimes it seems like EVERYONE is talking entirely too loud, or a kid crying infurates me or someone seems to be chewing like a horse.

The issue isn't really being irritated, it's how you express it. Knowing this about yourself is massively helpful. Instead of flying off the handle when some poor unfortunate soul enjoying thier dinner sounds like a wild animal instead of a civilized human being, or seems to be impersonating a human megaphone, you can stop and access the situation. Is the chewing/talking really that loud? Is it really that bad? Can you move on and ignore it? If not, would it be polite and appropriate in this situation to ask them to stop/speak more softly, etc?

Know that it's okay to be irritated. Not much you can do about how you feel, unfortunately, but your reaction is more within your control