Me and Caie (Caie and I?) both had an issue where our in-game voice chat wasn't working. For you everything looks ok - you can press your push-to-talk key and the "transmit" icon appears. But other players can't hear you, and the icon does not appear for them. It happens when in close proximity and using the radio channel. WTF?
It appears the game was not using the correct input device. You can't change the device from inside the game, but in Windows 10 you can actually change which sound devices each application uses in the "Sound settings". To fix it for us, we did the following:
- Alt+tab back to desktop, go to "Sound settings" (can just type "sound" in the start menu)
- At the bottom under "Advanced sound options", click "App volume and device preferences"
- Find Insurgency in the list of running programs, open the Input (bottom) dropdown - it will probably just say "Default"
- Pick the microphone you want to use explicitly
And that's it! Other people should be able to hear you in-game again. Shouldn't even need to restart the game, and the setting will be remembered in the future. Until it isn't. I actually had to make this change ages ago to force the game to use my standalone mic, but somewhere between game updates and Windows updates the setting got reset. Worth checking if your in-game voice stops working again.