AT&T 7720 사용자 설명서

After the two beeps, wait four seconds.  The system plays the
messages in Mailbox 1
— OR —
Press 1, then enter a Mailbox number (1 or 2), to play all messages in
that mailbox
— OR —
Press 2, then enter a Mailbox number (1 or 2), to play all new
messages in that mailbox

To repeat a message, press 4 while the message is playing.  Each
time you press 4, the system backs up one more message.
If you’re calling from a touch tone phone that sends a continuous
tone when you hold down a button, you can repeat part of a message
by pressing and holding down 4.  Release 4 to resume playing.

To skip a message, press and release 6 while the message is
playing.  Each time you press and release 6, the system advances one
more message.
If you’re calling from a touch tone phone that sends a continuous
tone when you hold down a button, you can skip part of a message
by pressing and holding down 6.

To stop message playback, press 5.

To save messages, hang up.

To play messages in another mailbox:
After playing messages in one mailbox, the system announces “End of 
messages” and beeps twice.  You can then press 1 (all messages) or
2 (new messages only) and enter the number of the other mailbox.

Connect with the answering system, and begin playing messages.

To delete a selected message, press 3 while the message is playing.

To delete all messages in a mailbox, after you listen to all
messages in the mailbox and hear “End of messages,” press 3 and
then the mailbox number.