Headset Operation; Considerations - AT&T Call Management System Supervizor's Manual

CMS Telephones and Telephone Programming
Hand/Headset Mute-optional. This button turns the microphone in the
headset (or handset) off so that the user can converse with another person
without the caller hearing the conversation.
NOTE:
The [Mute] button on your telephone will not work with headsets. If you want
to turn the microphone off while using a headset, you must use the
Hand/Headset Mute feature.

Headset Operation

To answer a call, press button with flashing light.
To
hang up a call, press [Headset Hangup] .
To mute the headset while on a call,
[Mute].
1 Press
2. Press [Mute] again to resume conversation.
To place a call, select a line button and dial the number.

Considerations

Headset Auto Answer can be activated and deactivated during a call
without disconnecting the caller and takes effect immediately.
A user with Headset Auto Answer active must manually select a line
button before making an inside or outside call.
A user can press [Speaker] to move the call from the headset to the
Speakerphone.
Headset Auto Answer does not automatically answer voice-announced
calls.
5-20 Optional Headset and Headset Adapter