Internet radio and excellent audio quality: dreamboat or reality?

Audio via the Internet gets more and more attention for program production as a contribution medium, for business to business distribution as a useful alternative to courier services, as well as a direct to home multi-media broadcasting service. Unfortunately the Web is still very narrow which means that in the case of a 28.8 kbps modem, the bit rate of the audio program is by a factor of 50 reduced compared with the bit rate used for CD. This means that high sophisticated compression techniques have to be applied to the audio signal before transmitting via the Internet. Subjective listening tests are presently the only tool to evaluate the audio quality of the compression schemes. Such tests with different type of typical broadcast material were performed at bit rates which are suitable for a 14.4 and 28.8 kbps modem, as well as for 1 B-channel ISDN with five different Internet radio audio coding systems. The background and the results of these tests, which have been conducted within the EBU B/IR (Broadcast Management: Internet Radio Project Group) according to ITU-T Recommendation P.80, are presented and discussed