Lucent Technologies MERLIN Plus Release 2 System Manual page 254

If the line is busy, or if you get no answer:
Touch Speaker to cancel the call.
1
Speaker
To use Monitor-on-Hold:
When you have been put on hold, touch Speaker.
1
Hang up.
2
When you hear the other person return to the call, lift your handset and
3
continue the call.
Speaker
To use Group Listening:
Without hanging up, touch Speaker, and continue your conversation.
1
Speaker
MERLIN Plus System Features
5-135