Others, like Magnitude Networks, are a sort of invisible broker for stations. Listeners receive these signals through audio player software, like RealAudio's RealPlayer or Microsoft's Media Player, which can be downloaded free at most radio Web sites. Like an old-fashioned transistor, the players grab the signal and reinterpret it as sound. Of course, the translation is not seamless. In fact, early computer radio was handicapped by the size of the files needed to hold sound.
Larger files take longer to download, of course, and are less likely to do so smoothly.
And soon, tuning in Web radio may not even require a computer. Through Macintosh iBook's wireless Internet connection, called an Air Port, and dozens of similar devices currently under development, and through the increasingly common cable modem hookups, which utilize existing cable television connections, Web radio is becoming detached from the computer modem. The ideal is something very like the familiar kitchen or bedside radio, a small, inexpensive receiver that does not have to be directly connected to a modem and that can find a place in any room in the house. Media watchers predict that such devices will be widely available within two years. These technological breakthroughs are happening at one of the most vulnerable times in commercial radio's 80-year history.