Does anybody know this?

[DuFresne]

I don't know why, but for the last two days of classes, I have been really gassy, with lots of nasty lower gastrointestinal activity. Whenever a bit of gas shifts within my large intestine, I know that I can hear it, but I simply can't tell if others can. If they have been able to hear it, then I must have the most polite classmates ever, because I get no indication whatsoever (I'd almost prefer if someone did turn to look, just so I'd know for sure). Are lower gastrointestinal noises generally heard by others, or are they totally within the body?