Um, so, like, do speech disfluencies matter? A parametric evaluation of filler sounds and words

Laske et al. (2024) asked college students to rate short speeches. The speeches had different numbers of filler sounds like "um" and "uh."

The researchers tested zero, five, or twelve fillers per minute. Listeners scored how effective and credible the speaker sounded.

Twelve fillers per minute hurt the speaker’s image. Five fillers per minute still looked okay.

Zero to five is the safe zone for sounding smooth and professional.

Montes et al. (2019) and Montes et al. (2021) showed that simple awareness training can cut filler use in college speakers. Their work gives you a ready-made fix for the problem Laske just measured.

Perrin et al. (2024) pushed the idea further. They used a computer program to teach awareness without a live coach. All four students dropped their fillers and liked the format.

Together these papers draw a clear line: keep fillers under five per minute, and if you need to get there, start with awareness training—live or online.

When you teach social or job-interview skills, count the client’s "ums" for one minute. If you hear more than five, run a quick awareness drill. Show a short video clip or use the free computer module from Perrin et al. (2024). One session is often enough to bring the rate back into the safe zone and protect the speaker’s credibility.