I use an "audiophile"-grade O2+ODAC - a slick little box which functions as an "external sound card". Built mine years ago from NwAvGuy's design (actually built six - seven? - of them over the years, for impressed friends and family and swiping ex-girlfriends, lol), but anyone can buy them from JDSLabs or other sources.
My first one was originally intended for an old gaming PC, but it works with any digital audio input or output (assuming you build or buy one compatible with whatever audio connectors you use). I've used mine with desktops, laptops, PCs, Macs, Windows, linux, Android, TVs, a stereo, smartphones, MP3 players. No messing around with software, firmware, drivers, apps, updates, settings, configurations ... just plug wires in, press power, and adjust volume. This is a longterm solution - you unplug the box from your old device and plug it into your new one, over and over again as years and technologies move forward, it just works, you never ever need to buy audio hardware or software again.
FiiO sells some nifty little gadgets of this type, as well. They seem popular with the "audiophile" crowd and generally receive good reviews. Not quite the same audio quality or power as the fat-smartphone-sized O2+ODAC, but still excellent and cheap and about the size of a matchbook, some have Bluetooth connectivity. I honestly don't know how well they might (or might not) work with hearing aids though I suspect that really has more to do with the headphones/speakers than the audio signal processing.
