Not all Basenjis are vocal…If you mean what we call a flat, (what's the difference between a condo and an apartment?) my boy lives in one - it's not ideal, but perfectly doable with plenty of walks. Somewhere (park in my case..) to let him off the leash so he can run is a must for me (others opinions may vary...)
Thankfully I am close to those who live above and below me because Oakley was horrible when his separation anxiety was bad..while he is super quiet its the whining, crying and howling from me leaving that others could clearly hear.
I was always worried about it. Luckily, his anxiety is much much better and while sometimes he will have his moments, it's few and far in between.