Can the programs do anything that a combination of cat and
   audioctl can't? Not to say that reducing the obscurity of the audio
   system is a bad idea, but exactly how much is the value-added?


as far as i can tell, audioctl & cat allow you to do almost everything
with our audiosystem that is possible..


these programs do re-use code from audioctl.. future work for this
includes a possible reimplementation of sun's "libaudio"/multimedia
audio interface, which while we have the kernel-level interface for
this quite happy, the userland library is not implemented.  several
audio packages on the net do not work under netbsd due to this
missing library...  but that might not happen, and is for "later"
anyway.