Can audio be passed between conferences without joining the conferences?

Hi, I’m evaluating Asterisk to replace a commercial product we are currently using on a project. We have one specific requirement which I’d be interested to know if Asterisk could support. In the paradigm of our system what we are trying to achieve is creating a conference which merges the audio output of two or more other conferences, without joining those two together. That may sound a bit off-the-wall, so by way of example: imagine conference 1 has participants ABC and conference 2 has participants DEF, and a supervisor wishes to listen in to both of these conferences, is this possible? In my mind, this is like setting up a new conference 3 with the outputs of 1 and 2 being inputs into it.

Furthermore, would it be possible for the supervisor to then talk on one of the conferences, whilst still monitoring the other? Once again, I see this as setting up the return audio path from conference 3 to, say, conference 1 but not to conference 2.

I hope all this makes some kind of sense, and I apologize for not being able to determine the answer from the documentation myself, which is very good. Any help greatly appreciated. Note that I don’t need any technical details at this stage.

I’ve never tried this but you may be able to use ChanSpy to listen into a conference in progress

Although it involves joining the conferences, you could see if you could join muted.