Lawrence's RealAudio^* Tool Page

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RealAudio is a technology that allows Internet or Intranet broadcast of various audio forms in "real time." What makes RealAudio different from many other forms of information transfer over such networks is that the audio file can begin to play immediately, rather than after a large down load of data. Thus, an organization can choose to make either a live broadcast over the network, such as CBC's live broadcast stream of news and events. Or it can prepackage the desired audio event into a number of different files for later access by various listeners, such as some of the CD music samplers that can be found in the tools section.

Progressive Networks, the developer of RealAudio, explain their technology as "streaming audio." What this means is that the RealAudio server receives the audio source, modifies it appropriately, and passes it on to the client in real time. There are devices known as splitters that allow for broadcast of the same signal to different clients. The timing of the broadcast is primarily controlled by the server. The broadcast is directed to the client who receives it via his Real Audio player. A more technical explanation of this process can be found in the RealMedia Technical Whitepaper.

In most cases, the RealAudio player operates though a world wide web browser of some description. Thus, the RealAudio specifications call for a browser that will support Netscape Plug-ins or the Active-X controls. The prime examples of this are Netscape Navigator or Microsoft Internet Explorer 3.0. If a point to point connection can be made through an Internet service provider, the RealAudio player does allow direct entry of URL addresses. The problem here is that it is very difficult to find these addresses without some form of browser.

The RealAudio player has a number of useful controls. As previously mentioned, it allows for direct entry of URL addresses. Thus audio files or live broadcasts can be brought in from various Internet or Intranet sources. The player also allows for access to files that have been saved to a local hard drive. Thus "RA" or "RAM" files can be down loaded and saved for future consumption. The player also has some error correction controls that allow the user to set acceptable loss levels. It should be kept in mind that any loss levels over 10 to 15% result in a very bad signal. The RealAudio connection is dropped when the level reaches above 50% for a short period of time. There is also a slide bar that allows for access to any point of a recorded RealAudio file. This is useful when you want an instant replay of sports scores or other useful stuff. This slide bar is inactive when the broadcast is "live". The final control is a simple volume control. This is very handy if the volume control on your PC is on the back of your sound card.

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There are a number of possible uses for RealAudio as it exists today. The tool section of this page lists a few examples of RealAudio's possible applications. Many of the functions are related to providing an expanded real time broadcast to a far flung audience. One prime example of this latter use is exhibited by CBC Radio. Their web site uses RealAudio extensively to provide real time and delayed broadcast of their news and entertainment services. There is one major advantage to structuring their web site in this manner. An international broadcasting system is expensive to build and maintain. The CBC can no longer afford such expenditures, thus Radio Canada International is slowly reducing its operations. The CBC web site can then take up where Radio Canada International leaves off. If someone wants to hear about Canadian news and events, they can access the web site. This would be a terrific opportunity to Canadians employed abroad. In a like manner, many local radio stations have used RealAudio to expand their markets tremendously. No longer is a radio station in the United States, Mexico, or Canada limited to the area that it can broadcast via FM or AM radio transmission. It can be listened to anywhere in the world by a much wider range of clients. The RealAudio server is also more cost effective than many other alternatives to traditional broadcast radio technology. Their is often a large cost associated with putting a radio station's signal over satellite or CATV systems. RealAudio server software can be purchased for $US 495. Thus it would be a relatively cheap addition to an organization's web site.

An extension to the general broadcast ability of RealAudio is its suitability for use in a "pay-per-listen" system. Some organizations use RealAudio's capabilities to provide audio services to their clients on a very select basis.This technology is also suitable for use within an Intranet system. Thus an organization can pass messages on to its employees, in real time, or prerecorded. In effect, they can replace public address and some voice mail systems through their network.

A further use of RealAudio is in its ability to provide a preview of audio products. Progressive Networks makes extensive use of this technology in its own site. They provide testimonials from satisfied customers within their hotlink program page. Another example of this type of application are the numerous CD music sellers listed in the Timecast site. The user hardware requirements for this type of application are generally greater than receiving a signal from a radio style broadcaster as stereo CD-quality audio generally requires at least a 28,800 bps modem. Monaural broadcasts like the CBC generally uses require only a 14,400 bps modem. Once a particular user has previewed the audio product he may purchase it from the vendor through a number of channels.

There are a number of add ons and new products being developed for use with RealAudio. One example of this is the text streaming capability that some of the RealAudio server sites are now displaying. Web site developers can now use Real Audio to provide audio information, while another program streams complementary text information to the end user. This would be extemely useful to news providers and various marketing organizations. Other applications are under development that would allow transmission of video or animation along with a RealAudio signal.

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^*RealAudio and RealMedia are trademarks of Progressive Networks.