If a capture device (like a capture card) is connected to your PC and set as the Audio Input default in Windows, all PC audio will transmit to other players when using the voice chat function, not just your voice. To fix this:

1. Set up your capture device.
2. Open your Windows Settings and select System.
3. Select Sound .
4. Choose the input device you want from the drop-down menu.

This will ensure your local PC audio is not transmitted over voice chat.