Here is a quick experiment I performed last night. With truly amazing band conditions, I made 2 simultaneous recordings using my Pappradio on my 2.2GHz laptop using DReaM and HDSDR software.
I've synced them here into a stereo file where left channel is analogue on 11725kHz, right channel is DRM on 11690kHz. RNZI runs the equivalent of 15.5kb bitrate AAC+ in mono on DRM.
As you see from the diagram, the AM is more processed/compressed, but as you listen, it is immediately evident that their DRM settings match their AM fidelity precisely. My audio file is in WAV, so there is no additional compression or noise reduction being applied. RNZI is really an example of excellence in broadcasting. Hats off to the crew over there!