Hello there! I'm glad to help you today!
Does this only happen when you're using Zoom program?
Have you checked permissions?
Open Settings > Privacy & security > Microphone.
Make sure Microphone access and Let apps access your microphone are turned ON.
Scroll down and check that Zoom has microphone access enabled.
If not, May I ask what is the make and model of your microphone? Have you also installed the drivers of your Microphone, if it has one?
May I ask what is the make and model of your computer? If you don't know the make and model or it's a custom, may I ask if you know the make and model of the motherboard?
Press Windows + R, type msinfo32, and hit Enter.
In the System Summary section, please provide me the three things below.
BaseBoard Manufacturer
BaseBoard Product
BaseBoard Version