It worked the very first match I had and then completely stopped.
I hope there is a solution, but if not then it doesn't matter too much.
Ensure NAT is not restricted.
Fix 5: Change the in-game audio settings For your voice chat to work correctly, you also need to make sure the in-game audio settings are properly set up.
If players are using a controller, plugging a headset into the controller will not allow the audio to come through.
My game is crashing.
Merciless Challenge tracking We fixed an issue where the Merciless Challenge was not tracking properly.
Also Read How to fix the 'Cold War voice chat not working' issue? So these are the fixes for your voice chat issue in Black Ops Cold War.