If a call is put on hold, and mic is still active, then your voice will keep the light on if you are talking. If you mute the call and then go on hold, then the light will go off, since your voice (talking) is not heard.
If a call is put on hold, and mic is still active, then your voice will keep the light on if you are talking. If you mute the call and then go on hold, then the light will go off, since your voice (talking) is not heard.