These are used by wandersweep.c .

-rw-r--r--   1 sw  staff   266 Apr 17 00:09 Makefile
-rw-r--r--   2 sw  staff  2627 Dec  9  2005 sound.c
-rw-r--r--   2 sw  staff  4505 Jan 26  2007 sound.h
-rw-r--r--   2 sw  staff  6443 Apr 14 21:23 sound_open.c
-rw-r--r--   2 sw  staff  1791 Jan 13  2004 sound_read.c
-rw-r--r--   2 sw  staff  1656 Jan 13  2004 sound_write.c

This ls -l style index was made with a php script.