This is a python plugin for xchat which implements
custom sounds on a per-channel basis.  It also includes
a command handler to enable or disable sounds without
the need to unload the plugin.  A custom sound can
be played whenever your nick appears in a message.

Installation is trivial, just load the plugin using xchat-s
plugin load interface.  Usually, just /load <path-to>/pnicksounds.py

Most xchat-compatible clients have a menu item to load this, and it
can be loaded automatically at startup.