||Announces a call placed from another phone on the telephone
||Announces a call incoming from the public network.
|Call back ring
||Announces a call back has been activated and will place the call
after the handset is lifted.
||Confirms acceptance of a keyed command, e.g. call back.
||Standard sound heard when handset is lifted and the line is ready to accept dialling.
||Normal tone heard when the called phone should be ringing.
||Normal tone heard when the called phone is in use ("engaged").
||Unusual tone heard if there are no lines currently available to the
||Advises that calls to this phone are being diverted. Confirms a
||Announces that an incoming (external) call is waiting. Injects a
tone onto the line that can drop fax and modem calls.
||Periodic tone warning that there are more than two parties involved in the call.
||Tone heard when there is a fault condition or the dialled number is not
allocated or handset left off.