Yes, the Kinect is not the issue. Even with the Kinect unplugged the mics are still muted for everyone.
On my old Elite Xbox 360 I could hear everyone through my tv fine. I had no headset though but it was ok because I could still hear people. Now on this new Kinect slim 360 the game won't let me hear anyone through my headset or mic. I They're muted because their names have the muted icon beside them, which is the symbol of a speaker with a red x on it.
This can be done manually, I would mute loud or annoying players myself. But now with this Kinect 360 it seems like they're ALL muted (maunally) although I have not set them to be muted. Nothing comes out of my tv or headset. When I first played I could hear them and myself but that was when I realized it was using the Kinect's mic. I didn't like that so I disabled the Kinect mic in the 360 settings. That was all I did.
Now the game does not recognize my headset either nor will it let me hear them. It's something with this Kinect. I've tried plugging it back in, unplugging it, plugging my headset in with kinect unplugged, plugging my headset in with Kinect plugged, it just doesn't work anymore and I've gone through all the game menus and settings, there isn't a real section for "mic settings" ..you can't really do anything in CoD settings besides muting single players and like I said they're already muted. I've tried unmuting them but there is no change and the X remains over their speaker beside their names.