Vertical Communications DSU and DSU II - Manual (Page 74)

8.2 Blocking Voice Announce Calls
You can prevent voice announcements from sounding over your
telephone speaker. This feature also blocks subdued off-hook voice
announcements as well.
•
To block voice-announced calls,
1. Press OPTIONS.
2. Press NEXT.
3. Press VAB.
4. Press ON.
5. Press SPEAKER to end.
•
To un-block voice-announced calls,
1. Press OPTIONS.
2. Press NEXT.
3. Press VAB.
4. Press OFF.
5. Press SPEAKER to end.
•
To block a SOHVA while you are on a call,
1. Press BLOCK.
Using The Other Telephone Features GCA70–245
8–2 LCD Speakerphone Reference Manual