Always receiving DTMF, while recording, playback, etc

I’m writting a interface on top of Asterisk, and have to be able to receive DTMF signals. However, I do no want to do it the standard way (i.e. play a voice menu which stops when a number is pressed). Instead I want to ALWAYS receive DTMF, whenever a user presses it, even during a conversation or during a playback, etc.

Then my interface can handle these DTMF events however I like.

Is this possible, and if so, how. I’ve tried both the manager API and the AGI interface, but both only give possiblities to temporarily receive DTMF, and not while playing using playback (i.e. the sound stops after pressing a DTMF button)

Not aware of a way to do it.