I think it's funny when people are talking to other people on the phone, particularly strangers, and when one of the people is supposed to be doing something (like looking up a date or time) that is traditionally a silent one, that person sometimes feels the need to make a noise, usually sounding like this:
This noise usually symbolizes two things:
"I am still on the phone"
"I am doing the discussed task"
I never make that noise, choosing instead to say something along the lines of
"If you don't mind, let me just look that up for you."