From Soundcore’s official Facebook page:
Soundcore’s currently (probably, arguably) most comfortable to sleep product is the recently released A40, so to be even better than that would require to be smaller. To be smaller, and yet keep 8+ hours battery life has to remove something. One thing it could remove is sound quality, a smaller speaker just to make white noise. You could also remove microphones and so cannot make/receive calls. Arguably sleep specific should not ring when phone rings (you’re trying to sleep). I suggest it should not remove ANC as whitenoise blocks higher frequencies and you need ANC to remove bass sounds. So still some microphones to detect sound to eliminate. To also keep Bluetooth as you go further into the ear requires intelligent antenna design.
Then there’s…