I am releasing Sound Notification based off of my prior vBulletin modification here.
There is a free and donate version.
Premium version will also sport no template edits, and install of custom profile fields when I have time to go more into the install scripting.
Only $5 for premium version!
Currently in Premium:
Play on Index Only
Different Notification Sound for Inbox and for Alerts
User Preferences to Disable
User Preferences to Set Custom URL for Sound
User Preferences to Set Volume of Sound
No Template Edits
No Creating Profile Fields
Anything you can suggest, drop me a line on XenForo.
You need to register, once you register an automatic message will be sent to you.