Old skool stuff: VOX

VOX (Voice Operated Transmit) is a feature that has been around for many years on LMR (and other electronic) equipment.  The feature essentially allows the radio to go into transmit mode without the user needing to press PTT. This allows them to work with both hands free. It's also useful in "call box" applications where there is no possibility (practical reason) to have a PTT button.

Originally, the VOX functionality was built into the microphone of a two-way radio but this required the microphone to get a DC voltage from the radio. The operation of VOX was also very rudimentary in that any noise on the microphone was sufficient to trigger the PTT. This often resulted in user frustration and some embarrassing situations. As a result, VOX was never really used.

MOTOTRBO radios employ software to control VOX operation. This means that only a valid voice input is sufficient to trigger PTT. This eliminates a large proportion of false triggers.

To configure VOX in a MOTOTRBO radio is fairly simple. In General Settings, you will need to decide on and select a sensitivity. One (1) is the most sensitive and you will need to experiment a bit before choosing a known-good value for your specific application.

In most cases, it makes sense to assign a button to turn VOX on and off. 

Then, in each channel, you need to enable VOX. So effectively, you could have channels with and without VOX enabled by default.

One thing to remember is that VOX operates as if Channel Free was selected - regardless of the selected channel admit criteria.

The difficulty with VOX will always be, that some things the radio operator may say, are not intended to be heard on the radio (e.g. what they say when they hit their finger with a hammer).