An audio-on-demand communication system provides real-time playback of
audio data transferred via telephone lines or other communication links.
One or more audio servers include memory banks which store compressed
audio data. At the request of a user at a subscriber PC, an audio server
transmits the compressed audio data over the communication link to the
subscriber PC. The subscriber PC receives and decompresses the
transmitted audio data in less than real-time using only the processing
power of the CPU within the subscriber PC. According to one aspect of the
present invention, high quality audio data compressed according to
lossless compression techniques is transmitted together with normal
quality audio data. According to another aspect of the present invention,
metadata, or extra data, such as text, captions, still images, etc., is
transmitted with audio data and is simultaneously displayed with
corresponding audio data. The audio-on-demand system also provides a
table of contents indicating significant divisions in the audio clip to
be played and allows the user immediate access to audio data at the
listed divisions. According to a further aspect of the present invention,
servers and subscriber PCs are dynamically allocated based upon
geographic location to provide the highest possible quality in the
communication link.