VOX — voice activation mode. In this mode, a radio operating in receive mode automatically switches to transmit mode when you start speaking. When speech ends, the transceiver returns to receive mode. The activation threshold (“voice volume”) is adjustable.
The VOX mode is convenient to use with a remote “hands free” headset. VOX can also operate without a headset. If the radio does not support VOX mode on its own, special headsets with built-in voice activation functionality are used.
This mode is convenient because it frees the hands. It allows full radio communication hands-free, for example, by securing it to a belt or placing it on a table nearby. The mode is indispensable when driving a car, riding a bicycle, skiing, and in similar situations.
Also, this mode can be used as a “baby monitor” or “audio guard”: the transceiver is placed in a room with a child (or in a secured area). When extraneous sounds occur, the transceiver will automatically switch to transmit mode and broadcast all sounds from the room until they cease.