MBP 2019 microphone issues

I used to have an issue where, instead of a clear voice, my mic would record (on screen recordings) or transmit terrible scratches and noise during meetings. The first time I faced this issue was about a year ago. I deleted a third-party screen recorder, and the problem went away, so I was sure it was a software issue. But now the problem has returned, and I'm only using the default screen recorder. Every time I need to record the screen or join a meeting, I have to check the settings first to ensure the mic is working correctly.

I rarely reboot my Mac. I've noticed that when the problem starts, if I turn the notebook upside down and gently tap the bottom a few times, the mic miraculously returns to normal.

What can I do to fix this problem? Could it be caused by dust inside or something else? Thanks in advance.

PS. It runs Sequoia but the problem appears earlier