I haven’t really investigated the newer ear buds, but it appears at first glance that those makers are coming at the issue from a different point of view, that of high quality audio first, then adapting to solve hearing issues. I hope the competition pushes the current HA makers into new and better audio designs!
From what I’ve been able to piece together, almost all HA’s available now use 16 bit D/A converters. I’ve concluded that until HA manufacturers start using 24 bit D/A converters instead of 16, they can’t really be serious about audio quality. Once they run the signal through the 16 bit D/A converter, all the fancy programming and software can never get good quality audio back.
They do amazingly well, especially with voice, considering this limitations, but it does put an upper limit on what they can do. Just using a 24 bit converter will not in any way guarantee good audio quality, as there is much more to it, but using a 16 bit converter makes it impossible. The good Audi’s are able to make the current crop work pretty well, but they are also hampered by the design limitations of the HA’s available now.