This fits in with what I believe about how we are triggered. It’s not the actual noise but the rudeness or insensitivity we perceive in it. On public transport recently I was triggered but a older gentleman sniffing repeatedly. After a couple of minutes though he found a hanky and blew his nose. After that, the occasional sniff didn’t bother me because he had tried. So many people don’t even seem to realise it is a terrible sounding rudeness to sniff loudly and repeatedly in public.