Mumble

To set up push to talk on Mumble. Click Configure –> Settings then under the audio tab select push to talk

Short Cut

You need to set up a short cut

Configure —> Settings.

Then add a short cut, here I am using the windows key.

Push to talk 2

Once this is set up you get a push to talk window, so you can either press this or press the key on the keyboard.

Push to talk