The Com.X PBX allows a spy feature to be enabled that allows the listener to listen in on calls in progress. Input from the listener will not be audible to the callers on the call being listened in to.
To listen in on all calls, enter the ChanSpy feature code. The first active channel will be listened in on. To cycle through the channels, use the * key. To increase or decrease the volume of the intercepted audio, use the # key.