Sony SPP-ID971 Operating Instructions Manual page 37

If you move or change your telephone company
Message waiting signals are sent in one of two ways: FSK signaling or
"stutter" signaling (Your telephone company can provide you with
more information about your service).
The first time this phone receives a voice mail message, it will set itself
to the FSK service and will lock out the stutter service if your
telephone company is in FSK service.
When you move or change your telephone company, you need to reset
this phone. To reset, perform the following procedure. The phone will
returns to ready state for either FSK or stutter dial tone voice mail
recognition.
To reset this phone
1
Press (PGM).
2
Press (#).
3
Turn Jog Dial up to make "RESET" flash and
press Jog Dial.
You will hear a long confirmation beep and the
phone is reset.
MESSAGES WAITING
LIGHT-OFF RESET
Caller ID Features
37 US