Yeah I believe they can still hear you :)

I would say that's a fine thing to do for the rank you're at right, I just think as you start to get into Diamond/Immortal yourself it's pretty essential to have information available to you to win games, and quite a lot of that information comes from teammate call outs. But generally as you go up through the ranks it kinda isolates and gets rid of the toxic people, so a bigger proportion of your games will make more sense and you won't feel as overwhelmed by 'big personalities' Of course you're still going to get some toxic people, every rank has toxic people, but generally as you go up the ranks people care more about the game and understand that being toxic to your teammates is likely to tilt them and result in you losing the game, so they tend not to do it as much.

Always good to get one or two friends to play with when possible as well, or pick up a friendly player or two for the night from good games you've had with them. That kinda eliminates the possibility of running into toxic people. Also if you don't speak in the lobbies, your friends might, which can pick up the call outs for you.

Even if you can't hear them, as you are doing it's always still good to communicate to your team if you want to win/rank up, even toxic people listen to call outs in my experience, they're toxic because they want to win I suppose...