HD radio is the first real innovation in radio since FM (frequency modulation) appeared in the late 1960’s.  Most people have heard ads about “hidden” stations on their radios, but rather than bringing stations out of hiding, HD crams more stations into the same amount of bandwidth.  These extra stations come to your radio as an extra signal that only HD units can intercept.

HD offers superior sound through digitalization, allowing more signal to reach the radio unit.  In the same way that a CD is superior to FM radio—cd’s carry more information than FM bandwidths—HD radio is said to be the ultimate in sound quality radio.  HD isn’t meant to replace current radio but to be used along with it.  Your radio will not stop broadcasting your favorite stations but you can greatly enhance the quality and numbers of stations to listen to if you purchase an HD receiver.

HD’s digitized signals eliminate interference and its signals don’t bounce off solid objects such as buildings.  Thus, the listener gets radio with no hiss or static.  The clear, crisp purity of HD radio has won many fans with its innovative technology.

Since HD signals leave extra bandwidth due to the compression of the digitized signals, there is room for more than one channel on a frequency.  AM and FM stations must each have their own frequency for their broadcasts but HD can fit two music channels and three talk channels on one frequency before the sound quality begins to deteriorate.  If you’re listening to a station on an HD unit, your receiver will alert you if there is more than one station broadcasting on the bandwidth (called “multicasting”).  You then have the option to listen to the program you originally wanted or you can turn a dial to receive one of the other channels on that bandwidth.  

HD can also display text such as artist information, stock prices, weather or sports.  Another advantage to HD is if the signal is lost on the station you are listening to, the unit will fade to the FM feed until it can pick up the digitized signal once more.

Unlike HD TV, there are no radios that will be obsolete because of HD radio technology.  Analog signals will continue to be broadcast right along with the digital signals and listeners can decide for themselves which form of broadcast they prefer.  Also unlike HD TV, the HD in HD radio doesn’t stand for “high definition”.  According to iBiquity Digital Corporation, the developer and licenser of HD radio, it doesn’t really stand for anything!

Consumers that want HD radio don’t even have to buy a special unit.  Kenwood, Panasonic and many other manufacturers of stereo and radio receivers, are selling upgrades to existing radios and stereo receivers.  In addition, there is no subscription fee involved with HD radio.  Other extras of HD radio not available yet include surround sound, real-time traffic reports by local stations, and a “rewind” feature that will allow a song that a listener just heard to be played later.  Entire programs will be able to be stored for later listening and eventually HD units will allow you to instantly purchase products advertised on the radio programs.  This could be quite convenient for listeners and very, very lucrative for advertisers. 

HD radios range in price from under one hundred to just over three hundred dollars, an unusually affordable range for such a recent innovation.  Many carmakers will be offering factory-installed HD radios beginning in 2009 and most radio stations are adopting HD technology or planning to in the near future.