From my initial experience I would say call quality is neither stellar (Bose) nor bad (Sony) .. Its seems to be solidly tucked in the middle and as a consequence perfectly acceptable. I was properly audible and the other party was as well .
And to reference another post, even Bose does not compare to good quality office headsets such as Plantronics Voyager Focus or Jabra Evolve 75 (I had the former and have now jumped to the latter as my go-to telco headset) . But these office headsets are only average anyway when it comes to music, as well as their ANC capabilities... Those headsets simply are not good enough for travelling...
So in their own class (travelling ANC cans) call quality on the DALI is fine. To my knowledge there are no headphones yet that are at the same time audiophile and have stellar ANC and have crystal clear call quality and a boom microphone and are perfect for travelling and and and and