AT&T 7406BIS - Manual (Page 51)

Speaker
Note: Your voice terminal is set for either the Speaker (listen-only) or the
Speakerphone (listen and talk) function. Check with your System Manager to see
which of these two features you can use.
Use the following procedures if your voice terminal is set for the Speaker (listen only)
feature.
To place a call without 1 Press [ Speaker ]
lifting the handset, or
Place call, or access selected feature
to use speaker with
2
any feature activity 3 Adjust speaker volume if necessary
(such as monitoring a
●
call on which you have
been put on hold, or
for group listening)
Note: In order for the
●
other party to hear
you, you must speak
through the handset.
To raise the volume, press the right half of the
Speaker Volume control button labeled [ ▲ ]; to
lower the volume, press the left half of the Speaker
volume control button labeled [ ▼ ]
If you have a display, it shows
[ SPEAKER L >>>> H ] (there are 8 possible volume
settings)