This video kind of/sort of explains it, but the maker of this instructional video is using an older version of Audacity. https://youtu.be/79M3LRPgI9M
But it should get you in the ballpark.
Hope that helps!
There are tolerance adjustments but Umm is primarily the letters "U & M" Which is prevalent in a high percentage of spoken words.
If you try to remove that sound automatically. It will make your audio as a whole suffer.
Try not to Umm as much as possible. Edit them out by manually by silencing them . I use Adobe Audition myself.
If you cut out/deleat all the Umm’s
err’s and Ahh’s. As the audio squeezes together. The audio will become out of sync with the video rather quickly when you import it back.
That’s why I silence unwanted noise,If I make a cut in the Editor later, everything stays in sync.
Although I have had some great quality using the Camtasia Audio Editing Tools too if the recording(s) of my narration or as I went along with the video on screen which I generally never do that way. If your mic is placed incorrectly or your background noises are not the greates for the enivronment you are in then those results will also bleed in to your audio. But, that is off of your question subject here.
Anyway, my suggestion would be to practice going by more of a script and leaving those Uhmm's and Ahh's or other things you do not want in your audio recording out of the picture. Just my suggestions here.
Joe is correct on his suggestions and you also have to keep in mind that using the Noise Removal can also bring in some other issues and they are not 100 percent but they usually if used correctly work good. Thanks for posting and let us know if you got your issue fixed or what you had to re-record your video and audio to correct it. Have a great day/night.
Like I stated I think the way you are going about it now would be your best option but this is just my suggestion. Have a great day/night and thanks for posting back.