In this tutorial we will reduce the internal microphone noise, which is due to the default amplification that many systems apply to audio input. The first thing we have to do is open a terminal (Ctrl + Alt + T) and enter the following command:

alsamixer

A sound equalization tool will open, we will press the Tab key to show different configuration panels, tabulate until the Capture view is shown (you can see it in the third line, as shown in the image), we move through the bars with the left and right arrows and adjust them with the up and down arrows.

The options should stay as:

Mic Boost: 0<>0
Capture: 100<>100
Internal Mic Boost: 0<>0 or 22<>22