Tabtip32!!
*TabletInputService to be more exact, the hand writing input service for Windows. If I stop this service iTunes keeps quiet.*
The tablet still works for Photoshop, as its drivers are still active, but not the system level writing recognition. Which is acceptable for me - though I prefer it on - but it's crappy for those actually using a tablet PC and iTunes.
I turned it off by right clicking on 'My Computer' and selecting 'Manage'. From there I selected the services panel and found 'Tablet PC Input Service', right clicked that and got properties. From there I stopped the service and set it to only start manually.
This works for me (kinda), but iTunes really shouldn't be activating sound feedback designed for the visually impaired because the pen input service is started. Seems like a bug to me.
Anyway, thanks for the hints everybody.