Sony SPP-A972 - Manual (Page 46)

46 US Telephone Features
Having a conference call (continued)
Switching conference from the handset to
the base unit
1
Press (HOLD) on the handset to put both lines on hold.
The LINE 1 and LINE 2 buttons on the handset and the base
unit flash.
2
Press (CONF) on the base unit to resume the conversation.
Switching conference from the base unit to
the handset
1
Press (HOLD) on the base unit to put both lines on hold.
The LINE 1 and LINE 2 buttons on the base unit and the
handset flash.
2
Press (CONF) on the handset to resume the conversation.
To join on the base unit while the handset is
talking on one line
Press the double flashing (LINE 1) or (LINE 2) on the base unit.
Now you can talk to the handset and to the line connected.
To join on the handset while the base unit is
talking on one line
Press the double flashing (LINE 1) or (LINE 2) on the handset.
Now you can talk to the base unit and to the line connected.
To join three-way conference (four-way
conference)
Press (LINE 1) or (LINE 2).