If you've ever read a verbatim transcript of an interview or conversation, you'll know that actual speech is anything but clear. When talking off the cuff, even the most clear minded people tend to ramble, um and ahh, double back, talk across each other, and jump between points and subjects. When listening to someone in person, our brains seem to edit what they say on the fly to make it comprehendible, focusing on th…
That said, "um and ahh" for filler is still vastly better than "like".