How to remove noise from microphone input?
Electret mics often have the rear open with an open weave cloth to keep out dust. It varies a lot between mics that look the same as balancing the front and rear air pressure to cancel is hard to match perfectly.

This helps to cancel far-field sounds like echoes off walls and distant noise that degrades the near-field voice signal to noise ratio.

Check your mic quality for this feature and test for far-field cancellation. Attenuating the input with the exact amount of cloth might help but is hard to balance. So often, mic selection is trial and error, unless they say this has excellent distant noise cancellation.

Also if you are using a speaker instead of a headset, positive feedback with full duplex audio will sound like echoes unless it has echo cancellation technology. ( side tone cancellation)