Sony SPP-A2770 - Manual (Page 63)

Answering Machine Features
Answering Machine Features
63 US
Erasing messages
To erase the message one by one
Press (ERASE) while the message is being played back.
You hear a voice guidance and the message is erased.
To erase the entire messages at once
Entire message deletion can only be made on the base unit.
You cannot erase the entire messages at once if there is a new message
that has not yet been played back.
Press (ERASE).
You hear a voice guidance “All of your messages have been
erased” and then the entire messages are erased.
Note
If a power interruption occurs or the AC power adaptor is disconnected while
erasing a message, all recorded message may be erased.