Sorry for the convoluted question but I'm not sure how to ask this. These examples should make it clear what I'm talking about:
"Well, hum... you know."
"It's, huh... there!"
"Hm... now where were we?"
Basically, it's something you say while you're thinking, maybe to let the other party know that you're going to start speaking soon or that you're going to continue with your thought.
My questions is, is there a name for these expressions that I can use so I can talk about them?