[racket] sound.ss teachpack

Hello.  What happened to the sound.ss teachpack, which apparently used
to include speak-word and speak-list methods.  Those sound great fun
for teaching ... but I can't find any evidence on the Web that it ever
existed, except for Google Books hits on HtDP :).  (Note that there is
a deinprogramm/sound.ss file in the current distro, but that just
plays sound files, which is less cool.)

Thanks,
John