Yes they can see that you did it. There is a pop-up in the bottom.
From a tech site:
- Anyone in a Google Meet conference can mute anyone else.
- If you mute someone, no one in the conference will be able to hear them.
- When you mute someone, everyone will be notified that you have muted the person.
- You cannot unmute someone once they have been muted. They have to unmute themselves.
