Open the Symphony Preferences panel from File->Preferences... and make sure that the check box named "Support assistive technology tools " is checked. If not check, please check it and restart Symphony.
Start an AT tool which support IAccessible2 such as JAWS, NVDA (They also can be started before Symphony). For example:
Now the AT tools can read UI and document content from Symphony application. You can operate Symphony by listen to the AT tools.
If you want to disable accessibility feature in Symphony, make sure the check box is unchecked.