Can't use voice chat in Garry's mod. HELP D:

Have you got a key bound to push to talk?

Edit: Just watched the vid. Try switching to windowed mode. It should allow you to see the menu sliders properly.

Sorry for this bump, but I really need to know if someone knows the answer or also has the problem.

Have you tried pressing the Push-To-Talk key while doing the microphone test?
Also: Set your key binds to default and see if that helps

Does your mic work outside of steam?
Try rebinding the button and check the mic under steam settings?

Just so you know, binding your Steam and source games to push-and-talk inexplicably causes it not to function on some systems. Try disabling push-to-talk on Steam if it's on and only have it used in-game.

If not, then I'm not sure what's going on unless you have the microphone in-game selected to the wrong jack.

i had the same problem in counter strike source all i did was enter the options then keybord . search for communication u will get the button change it to T or any button . i hope i helped if i did not i hope someone will be able to.