As Lennart observes, yes, indeed, Linux rarely removes drivers for old hardware,
mainly when there is something broken about the driver that makes it
troublesome to continue to fix it
I took a peek at Linux kernels going into the moderately distant past, and
the M-Audio Audiophile 2496 is based on a chipset called "Envy24" or
"ICE1712", and there is a fairly sizable list of PCI sound cards using
that hardware, which points to it being reasonable to expect it to be
supported for a good while. I see support in both latest (4.4) and
pretty old (3.18) kernels, all using a kernel module called snd-ice1712.
Loui Chang's suggestions of audio tools like ffmpeg, mplayer, flac, metaflac, lame, mutagen
seem likely to be helpful. Unfortunately, a lot of the literature on
sound tools points towards friendly graphical tools that won't be
friendly at all to anyone having difficulty seeing the screen.
I suspect that this is enough of a specialty area that it may be
necessary to look to a topic-related group rather than a
geographically oriented group.
One mailing list I can point to offhand that seems likely to be
relevant is debian-accessibility, which is the place where
discussions take place for accessibility-related issues on
Debian.
https://lists.debian.org/debian-accessibility/