While in a Zoom or Google Meet session on a Chromebook, the participant sounds quite loud with a lot of static to the other meeting members. This typically happens after unplugging a headset with a microphone and the participant is speaking with the built-in Chromebook microphone.
The Chromebook amplifies the voice while the headset microphone is plugged in and keeps that amplified setting when the headset is unplugged.
Click on the clock in the bottom right corner
Click on the arrow to the right of the volume slider
Move the volume slider that is under the "Input" heading, just a little bit
This will update the Chromebook that there is no headset plugged in, and to stop amplifying the audio for the built-in microphone