NBC's "Heroes" is now in its 2nd season, and the underlying theme of recent episodes revolves around an evolution in humans that's causing its characters to have special powers (uhm, can you tell I'm a fan?). The interesting aspect is that this evolution has been rapidly increased recently, causing more mutations to occur at a faster pace.

Ok, so Sirius and XM are right now arguing that they face competition from other audio services like AM/FM radio (who garner something like 96% of all radio listening... not entirely surprising since radio has been around commercially for around 80 years). In that audio mix, Sirius and XM argue that other options like Internet radio, streaming audio on cell phones, MP3 players and various other audio technologies also serve as competition.

But just like the evolution we see in "Heroes," the evolution of audio entertainment has been rapidly increasing as of late. The options available to the consumer have intensified in just the eight months since Sirius and XM announced their merger.

Even in this short amount of time, there's been an exponential growth in audio devices ("mutations" maybe? I don't know if I can go that far in the analogy, but you get it). So let's take a look at what has affected how we listen to audio, and what will be changing how we define "radio" in the years to come:

iPhone
Of course you have to bring the iPhone into this. Back in 1997 - let alone just 8 months ago - a cell phone was just a cell phone. Now mobile phones come equipped with audio playback, storage and over-the-air streaming capabilities. The consumer looks at a "cell phone" less and less as simply a "phone" and more and more as a mobile access system... and the iPhone personifies that. We all know the iPhone's evolution is not going to stop (it took a couple generations of the iPod before it truly began to take off). Of course, other phones (like the LG Muziq) are equipped with audio capabilities, and that's only going to continue to evolve.

The new iPod series
The new iPod Nano, Classic and Touch bring video and music together. And the Touch, like the iPhone, allows wireless downloads of music directly from the iTunes store in countless Wi-Fi hotspots around the country. Hear a song in Starbucks? Buy it instantaneously. Tag songs heard on HD Radio, and purchase them through iTunes. There's no doubt that iPod/iTunes is its own audio eco-system, and Apple is showing no signs in relenting its continuous evolvution of this platform. More than anything, the iPod has revolutionized how we listen to music (and time-shifted programming like podcasts). And the biggest thing to remember is that the iPod is only 6 years old.

HD Radio
In March 2007, the FCC gave the green light to HD Radio. With this new technology (and a new receiver), radio fans can listen to multiple streams of higher-quality, digital programming. But most radio listening is done in the car, and this hasn't escaped the massive media companies that are pushing this technology. BMW, Ford, Lincoln and Mercury all offer HD Radio receivers as a factory-installed option and Sony has come out with the XDR-S3HD table radio and XT-100HD car radio... and there's more to come.

Customizable Radio
Slacker's "Personalized Radio" enables consumers to customize their own radio stations and listen to them wherever they happen to be. Slacker has been streaming online for a while, and now that it has deals with the all the major record labels, will soon be available via WiFi and in automobiles via satellite.

WiFi DAPs and Radios
With the Sansa Connect, consumers can stream Internet radio from Launchcast stations, browse Flickr photo streams and sign up for Yahoo's portable music subscription service, Yahoo Music Unlimited To Go, to download any tracks or albums over Wi-Fi. Pandora also will have its own WiFi Portable Radio available, where you can listen to the Pandora customizable radio over-the-air wherever you have access. And let's not forget the Phoenix WiFi Radio, which virtually eliminates the need for a traditional alarm clock.

Ford SYNC
The Ford SYNC, which starts shipping in automobiles this fall, allows drivers to control a myriad of audio entertainment options through a single built-in interface. SYNC uses a hands-free in-vehicle Microsoft operating system that can switch seamlessly between devices like iPods, Zunes and cell phones to play MP3s and internet radio services like Pandora or mSpot. Standard on all of Ford's top models – which is about 40% of Ford's sales – it will be available for sale on their other models.

Sprint Xohm
Sprint has announced the roll-out schedule for its nationwide high-speed WiMax network: Sprint Xohm. Sprint plans WiMAX test service in the Chicago, Baltimore and Washington, D.C. areas by year-end 2007. Samsung has been awarded the infrastructure build out for the New York area market, Washington, D.C., Baltimore, Philadelphia, Boston and Providence, R.I. Xohm is expected to be available in a number of markets starting April 2008 and expected to cover 100 million people by year-end 2008 thanks to their partnership with Clearwire. Think WiMax is years away? Think again.

Remember, the world of audio has changed dramatically since Sirius and XM received their licenses in 1997. Even the Sirius-XM merger's biggest opponent, the NAB, has commented about the "...seismic explosion in alternative media sources in the last 30 years..." (Dennis Wharton, Executive VP, NAB, Communications Daily, "Tribune Seeks FCC TV Waivers for $8.2 Billion Sale", 05.07.07).

NAB President and CEO, David Rehr, may have said it best when he stated, "barely a day passes without the introduction of a new competing device or service." (David K. Rehr, 2006 NAB Radio Show, September 21, 2006).

The last eight months shows the pace of the audio evolution, and the ever-expanding array of options available to consumers, continuing to accelerate. And maybe they're not mutations so to speak, but the convergence of devices is growing at an exponential pace, and will forever change the way we listen to "radio" ever again.