This might be an overhead for most of the people who are into making video tutorials. I personally had this issue because I have no good mic. Here is my solution to reduce the noise in such case.
Tools :
1) VokoScreen - To record the screen
2) Audacity - To reduce the noise
3) Shotcut - To Edit the video/audio and Export
OS:
Ubuntu 18:04 LTS
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Intro Video: RGJ