All three of my cats have different "voices". I can tell by the sounds what they are doing, if two of them are "wrestling", and which two it is. And I can if two of them are actually "fighting", which is pretty rare, and which ones it is just by the sounds.
I've had cats all my life, I think they may understand specific words, but they definitely understand they sound of your voice if you've had them awhile. Mine know the sounds of our voices if we are feeding them, playing with them, scolding them, warning them, etc... Some people think they know their names, maybe, but I think they know the sound of your voice when you are calling them. Have a complete stranger call the same name and you will get no response normally.
