Does your cat respond when you call their name?

I have three cats, and one of them often comes when I call her. They all know their names because when more than one of them is in the room and they hear their name, their ears will twitch but not when I'm talking to another one. The ear twitch is pretty much their only "tell" though, because the other two are unlikely to so much as look at me when I call them. If not for the ear twitch, I would wonder if perhaps they were deaf. However, I can barely whisper their name and get the ear twitch response, although it doesn't work too many times in a row. Cutie though, she will come at least half the time when I call her, which is okay for a cat.