Had one this morning when I got into work. I'm a library assistant at a small college library and my boss works next to me at the big desk. We were taking about something in normal, or below normal voices, and this student comes up to me and asks me to lower my voice as she can't hear the student next to her (who is actually rather soft spoken).
Now I was talking in abnormal, or lower than normal voice, as its study week and we get a lot of stents in here. But, as its study week we have LOTS of them coming in here and making noise, making a lot more noise than we were my boss and I were just astounded that she'd even think of requesting something, she said "Yes, ok to the girl' (as we can't tell the students off as they bring in $$$$) and we started talking again, both of us astonished.
But it gets better! 20 minutes later we had a whole crowd of students in there being rather loud, not very but louder than I was. She didn't say anything to them, of course, and we just watched to see if they were going to stay and be loud before we said anything. (they weren't, they dispersed)
An hour after she talked to me, her group at the table were being loud, as in we could hear them for, where we sat half way across the room. And this was in a social 'talking and laughing' kind of way that DOES disturb other students. I have to confess there was a bit of small bit of satisfaction I felt when I went over to her group and politely asked them to lower their voices, as we can hear you all the way at the desk.