You can look at help /msg and also look at /help on open . And then add a sound to evey event..
; Will play on all private messages to you
on *:text:*:?:{
/splay path/to/sound/file.mp3
}
; Will play on all channel messages
on *:text:*:#:{
/splay path/to/sound/file.mp3
}
; Will play a sound when you get a query
on *:OPEN:?:*: {
/splay path/to/sound/file.mp3
}
This end up in your remote. ALT + R in mirc.
;- edit
You can use a line if you want to ignore some channels.
on *:text:*:#:{
if ($chan != #some_channel) && ($chan != #anothet_channel) {
/splay path/to/sound/file.mp3
}