This program listens for sound. If it detects any, it starts recording
automatically and also automatically stops when things become silent again.

In order to use this, a few steps need to be completed first:

1. Remove the line: filter = ./my_filter2.so.0.1 0 3000.0 1.0
   from /etc/listener.conf.

2. Run setlistener (as an ordinary user), and use the
   cursor keys on your keybord to move the "|" left and right until <silence>
   appears in place of <SOUND!>. Make a note of the "Current detection level",
   and modify the detect_level value in /etc/listener.conf to match.

3. To start, run listener -f (to prevent it forking to the background. Omit -f
   if you wish to fork). Output will be saved in the current directory as a
   wav file by default.

Requires libsndfile, available at SlackBuilds.org