On National Public Radio stations, it was always so impressive to me how the announcers and interviewees can speak so smoothly, with very little hesitations, stumbling, and almost no uhs and ums. They did a fascinating segment a year or two ago about their editing. They do edit out most of those hesitation sounds, heavy breathing sounds, stuttering over a syllable, etc. That’s how it seems like people can talk for 15 minutes and not have those fillers and pauses in there.
They aired before and after tracks, and also clips of just the removed sounds, and just from the breathing, pauses, and uhs, you can tell who they are.
audio (real media): http://www.wnyc.org/stream/ram.py?file=raotm/otm123104d.ra