@liaizon haven't done any work in actual transcription, but I'd assume there's research into it (though I did at some point have to look at some transcribed speech and for fun I just pulled up transcriptions of the Switchboard corpus, opened just any random file and:

have uh the thing that that bothers me worse than the credit cards i think is uh you mentioned the gasoline credit card
[...]
i don't have that but i've got you know one of the [vocalized-noise] the
[...]
uh instant teller cards

it's incredible that during normal conversations unless you pay attention you don't notice the mess that comes out of your mouth because brain good