An Audio Caller ID service is provided which permits the calling party to
speak a real time audio message that can be received and played by the
called party's Caller ID equipment while his telephone equipment remains
in the "on-hook" state. A calling party which has Audio Caller ID (ACID)
service would speak a short audio message before dialing the called
party. That message is converted to digital form, optionally compressed,
and transferred to the called party in a manner similar to conventional
Caller ID information. The called party's Caller ID equipment operates in
the conventional manner, except that the received Audio Caller ID signal
is recognized as an audio signal. At the site of the called party, a
decoder is provided to convert the digital signal to an analog audio
signal, and this analog signal is provided to a speaker, which plays back
the calling party's audio message.