Why we use filler words like "blah, blah, blah", “yadda, yadda, yadda”, and “dah dah dah dah dah”

[@seanwebb605]

But what about a doo doo doo a da da da?

[@seanwebb605]

I called it.

[@FranklynMonk]

Were there any subtitles from the clips they played?