the mixer

Once listeners have downloaded the right player they can
decompress the converted signal from binary back to analogue and
play it on their computer. Plug-in software RealAudio Player must
be installed and the currentfree G2 RealPlayer is available here

PC/Mac Specs

A computer with a sound card and speakers to play audio (external
speakers can be used to supplement small built-in speakers)

Minimum requirements for RealPlayer G2: 
90MHz Pentium processor or equivalent, 16MB of RAM, 14.4Kbps modem
(audio only); 28.8Kpbs modem (video), 16-bit sound card and
speakers, 65,000-color video display card (video), Windows 95
operating system, Internet connection and web browser. 

Mac OS 8.1 or later, 32 MB RAM, 65MB virtual memory, 604
PowerPC (200 MHz or better), Internet connection, Browser

The RealAudio player plays the file as it is being
downloaded A congested network can affect the signal and quality
of sound. For this reason, the plug-in employs "buffers" which
ensure a signals safe passage across the Internet.