Yes, you can mute other people's audio as well as turn off their video. This applies to your individual perspective only.
You can mute one or more peoples' audios and video steams while in a room. This control will only affect what you are hearing and seeing. Meanwhile, each person can mute their own audio or turn off their own video steam.
To mute someone's audio, hover over their video bubble and click on the microphone icon. You can restore the audio by clicking the icon again.
To turn off someone's video stream, hover over their video bubble and click on the video icon. As a result, you will see their profile picture inside of their bubble instead of an active video stream. You can restore the video by clicking the icon again.