Microphone input device and input/output volume can be adjusted from settings.
For output volume, you can adjust the sound for “videos/BGM”, “Sound Effects”, “Voice”, and “World” separately.
Input volume allows you to control the volume for the microphone.
About microphone input devices
For Quest2, the default name for all OS devices will be “Android…”.
For mobile, the default name for bluetooth devices will be “bluetoothHFT”