1 - You didnt list the make and model of webcam + Mic
2 - You didnt list software used in the recording process

3 - Are you using OBS or simple screen recorder
or
Audacity (sound) with GNVIew (webcam)

_______________________________

99% of 'webcams' are software based
thus it will use the CPU grunt for the processing

THUS

Hardware XLR audio interfaces with XLR mics
will be processed QUICKER
then software video streams from the webcam
thus you will need to artifcally make a delay in the audio for the video to be synced

I gave up on webcams and now use an

*  USB HDMI capture card - 20-30 bucks from Aliexpress

*  Presonus Audiobox USB audio interface

*  Action cam with Micro HDMI out, then with an Micro HDMI to HDMI adapter ,
connected to the Capture card
which then connects to PC via USB2

-------

Update:

vokoscreenNG is sh1th0use software

1 - uses ((( github)))
https://github.com/vkohaupt/vokoscreenNG

2 - seens to use QT5 and openSSL , pulseaudio and libwayland

3 - no appimage or .deb file

Thus it sucks

Solution - Gitgud

Use OBS or Simple Screen Recorder

I have a webcam with integrated microphone and separately I have bought a professional microphone with minijack connection. If I use the webcam, when recording with vokoscreen a very annoying background noise appears and that I have disabled the webcam microphone with alsamixer and pavucontrol. When I do not use the webcam, the background noise does not appear. Any suggestions before buying another webcam without microphone?

Thanks