In Sounds of Shirc, if you assigned a sound for new channel message, you got that sound played for every new message. This could get really annoying - not only because when I am in another app, I keep hearing noises while I've not got around to switching back to ShadowIRC, but also because it makes that sound even when I actually have the channel window focused.
ChannelBar helped fix this with its audible alert feature, which let me have a beep played on receipt of the first new message in any un-focused channel window; however, this is a ChannelBar-specific feature and doesn't help for people who want custom sounds but not ChannelBar.
Should something be done to the plugin API events system to allow plugins to be notified of the first new IM in an idle window (and maybe repeat this event every 5 minutes if ignored, in case you were AFK)? Or is this purely a matter for a sounds plugin to take care of by itself?