Causes
Try restarting your device. Open Google Home app and select the device you are trying to reboot. Go to Settings (three vertical dots in the upper right corner of the device card) and tap More and then Reboot.
or
Unplug the device for roughly a minute, and then it plug back into the power source. Allow the device to reboot itself.
Go to myactivity.google.com and listen to the voice recordings that your device is picking up. If you hear static or bad quality recordings contact Google Home Support. The "Contact Us" option will be in the upper right hand corner of this page.
Your Google Home may need a complete reset to default factory settings in order to fix the issue. This action cannot be undone and you’ll need to set up the device again.
If nothing else is working: press and hold the mute button on the back of your Google Home for about 15 seconds. You'll hear your Google Assistant confirm that it's resetting Google Home.