The chat tone (a sound played when the unit speaks) no longer plays when the unit speaks.

I have tried to pin down the cause - at first thinking it might have been related to my CSU, but even removing and rebooting without the CSU has not solved the issue.

I have tried:
1. Disabling and re-enabling the chat tone under manage->feedback
2. Switching personality profiles
3. Switching personality profiles and rebooting
4. Doing an @module probe

I'm not sure what the cause of the bug might be.