Seems the app would also have to filter-out the sounds of hands
pounding the keyboard, hair being torn out, and the gnashing of teeth.

Have you considered any of the "Shuttle" systems? One client I had
in 2006 had a ton of those running various Linux distros, and NASA's
Ames Research Center essentially cobbled-up a supercomputer using over
1000 of them networked together. NewEgg <http://www.newegg.com> seems
to be the preferred vendor for Shuttles. Nice thing about Shuttles is
their size -- the proverbial cigar box -- and they can be stacked
atop one another.