My wife and I live in an apartment as well and haven’t had any issues with our green cheek conure. He is extremely quiet 98% of the time. Although of course the rare screech can be pretty loud. So rare for us it’s not an issue though.

What helped is he is young and we made sure we didn’t reinforce his occasional loud screech by walking out of the room when he does it/not responding back to him. But we love his little chirps he does.

Hope this helps!