AT&T PARTNER II Release 3.1 Programming And Use Instructions page 184

Standard Phone
To make an announcement over the loudspeaker paging system:
1. Lift the handset.
You hear intercom dial tone.
Dial [ ] [ ].
2.
7 0
Speak into the handset.
3.
Your voice is heard through the loudspeaker system.
For touch-tone phones only, if your paging system supports announcements to
zoned areas, refer to the instructions packaged with the device to make zoned
announcements.
5-101
Loudspeaker Paging