The Free On-line Dictionary of Computing (30 December 2018):

RealAudio

    A program from Real Media for playing
   audio over the Internet, and the lossy audio compression
   format it uses.

   The system is implemented as a client/server architecture.
   The RealAudio server incorporates an encoder which
   compresses sound into RealAudio files.  The client side is a
   web browser plug-in or add-on (a recent version of
   Internet Explorer apparently has built-in support for
   RealAudio) which allows the stream of data sent from the
   server to be uncompressed and output using the normal sound
   facilities of the computer, such as a sound card.

   A 14.4 KBps or better modem is required, and a 28.8 KBps
   connection is recommended for music-quality sound.

   (http://realaudio.com/).

   (2001-12-13)