If Google Assistant voice commands aren’t working, it’s usually due to an issue with the Google app. Some of the most common issues include incorrect permissions preventing the Google app from accessing your microphone, accidentally disabling voice commands, and corrupt data within the app.
If your Google Assistant isn't accepting voice commands, try each of the following solutions, in order, until it works again. If it still doesn't work after trying all of these solutions, you may need to wait for Google to address the specific issue you're experiencing.
Google Assistant needs permission to access many different systems on your phone. For example, it needs access to your microphone, otherwise it can’t hear your voice commands at all.
If Google Assistant voice commands aren’t working on your phone, the first thing you should check is the permissions. If you see that any of the permissions are disabled, enabling them will likely fix the problem.