Avaya T3 (IP) Comfort - Manual (Page 146)

Headset
146
Auxiliary devices*
Headset - setting monitoring/handsfree on the telephone
You can switch on monitoring on the telephone or handsfree calling via the tele-
phone while you are telephoning with the headset.
Switching on monitoring
Scroll to the Monitoring on menu item.
Confirm your selection. You can then hear the caller through the built-in loud-
speaker.
... switching it off
Scroll to the Monitoring off menu item.
Confirm your selection.
Switching on handsfree
Scroll to the Handsfree menu item.
Confirm your selection. You can hear the caller through the built-in loudspeaker
and can speak to them using the built-in microphone. The headset is switched off.
... switching it off
Press the "Handsfree / monitoring" function key. You can telephone using the
headset again.