VOX stands for ‘voice activated transmission’ or ‘voice-operated exchange’ and is used to broadcast without having to use PTT. The advantage of this feature is you can talk hands-free.  When VOX is enabled, the microphone listens for your voice and when you start talking, the All Road automatically starts transmitting and stops when you finish talking.  VOX is useful for communicating without the use of your hands to operate the All Road.  It is useful while driving or in situations where you need to keep both hands on the wheel.  Please note that VOX can sometimes be triggered by background noise.  If this happens, simply use the normal PTT to control the transmitter.