AT&T 993 2-Line - Manual (Page 34)

3
Telephone operation
Basic operation
Make, answer or end a call
Headset
Make sure the headset is plugged into the headset
jack. There will be a low pitch (error) tone if you press
HEADSET when the headset is not plugged in.
To make a call, press and release HEADSET. The HEADSET
light goes on. Wait for a dial tone, then dial the call. The
number appears on screen when dialing.
To answer a call, press HEADSET.
To override automatic line selection, press HEADSET,
then press and release a
LINE button. Dial the number
within twenty seconds.
— OR —
Press the
LINE button for the desired line, then press
HEADSET. Dial the number within twenty seconds.
NOTE: If speakerphone is programmed as the default mode (See Set
preferred mode on page 2), you must press HEADSET to activate
the headset.
Switch between handset, headset and speakerphone
To switch from handset to headset or speakerphone,
press
HEADSET or SPEAKER, then replace the handset.
(In order to use the headset, it must be firmly plugged in.)
To switch from speakerphone to handset, lift the
handset. (Do not press
SPEAKER, or the call will be
disconnected.)
To switch from headset to handset when the handset is
in the telephone base, lift the handset.
To switch from handset to headset when the handset is
off-hook, press
HEADSET.
To switch from headset to speakerphone, press SPEAKER.
To switch from speakerphone to headset, insert the
headset plug into the jack firmly, and press
HEADSET.