I'm not seeing that on this end. Here, it just beeps.
This is the Planet Voice Assistant.
It makes a little chirp. If you haven't set up Voice Assistant, then nothing else happens.
You can disable this from Settings : Cosmo Settings ("Right toggle button activates voice assistant") if you don't want it.
If you go into Planet Voice Assistant, you can tell it to use Google Voice Assistant, which is currently the only option. I guess PC eventually want to make their own?
Then, after you hear that chirp, you can use any of the Google Voice things like "remind me in an hour and a half to eat nine pies".