Mush Client Chat System: How to add sounds to messages?

Hello! I'm testing the chat system in mush client, I have to say that it is great.
I want to add sounds to messages, when someone connects and other events, through the function Sound() but I don't know how to do it, because the strings that shows the chat are not captured by the triggers.
How can I do it?
Many thanks.

See: http://www.gammon.com.au/scripts/doc.php?general=plugin_callbacks

Scroll down to Chat System Callbacks.

If you make a plugin that has the OnPluginChatMessage function in it, you can make it play a sound.

http://www.gammon.com.au/scripts/doc.php?function=Sound