VOX stands for voice-operated exchanged or more commonly known as voice activated transmission.
Every two way radio or walkie talkie has the use of a PTT (push to talk) button which allows you to transmit audio to other users. However, certain models have the VOX feature which means they can be used hands free. With the VOX feature switched on, the radio microphone is always listening. This means it will automatically start and end a transmission once it hears your voice.
Many people operating radios, know there’s an important function in the radio, called radio alarm. Though not frequently using, when you are in emergency, this function can help ask your partners comes to “rescue/help” you in time. Such as when you are a security man, you find someone who is very suspicious to be a thief. Then just press your radio alarm button. Partners whose radio you can communicate with can hear the “alarm”ringing on their radio also, they will come to you and help you.