"As more and more people are investing in video, they find they want better audio to go with it," said Jennifer Boone, audio manager for Consumer Electronics Association. And not just for movies — for music, too.

But what exactly is high-definition audio?

"HD audio is a term CEA is using to promote the idea that there is higher quality audio out there — better quality than a CD," Boone said. Technically that means resolutions greater than 16-bit/44.1kHz and without compression that causes information to be lost, as is the case with MP3 files.

Some high-definition music formats have been around for years. What's new is that mainstream consumers are showing interest as more high-definition music is being offered in three forms — surround sound music discs, high-definition downloads and high-definition radio.

Surround sound music discs

As more people add surround sound systems to their TVs, it's not surprising they want to use them for music when they aren't watching movies.

"We have clients who are already doing it," said Jimmy Coiner, programmer at Media One, a custom audiovisual retailer in Lenexa.

Music producers are taking notice. Monster Music  has begun producing high-definition, multi-channel recordings that can be played on any DVD player. An accompanying second disc plays in standard CD players so you don't have to buy your favorite albums twice. Prices range from $16 to $30. A classic example is the new George Benson and Al Jarreau - Givin' it up DVD.

Givin' It Up features a stunning collection of smooth, seductive grooves and inspired reinterpretations of Benson's and Jarreau's most classic songs, from "Breezin" and "Every Time You Go Away" to "God Bless the Child." All of these songs the pair played lives at a private Monster party at the CES Show in January. The pair play in Sydney soon.

Higher-fidelity CDs have been around for more than five years, in the form of SACD (Super Audio Compact Disc) and DVD-Audio recordings (see Audio Lingo box). But those formats were never widely embraced. For one thing, they had to be played on special players. Also, the quality was iffy on some early recordings.

"Recording engineers didn't know how to place the mics," said Al Eckilson, owner of Primus Audio. "It's taken a few years. Now they've learned how to properly record the music."

Speaking at a high-definition audio event at the electronics show in Las Vegas, Ray Kimble, owner of Kimber Kable of Ogden, Utah, said more than 700 new SACD titles were released in the last year, bringing the total to more than 4,000 albums of all genres from rap to classical to rock.

Not all SACDs are multi-channel (surround) recordings, but most are, Kimble said. In addition, many SACD discs are hybrids, meaning they will play on SACD players or standard CD players. SACDs can also be played on Sony PlayStation 3 game systems and some (but not all) new DVD players, including some in the under-$300 range.

High-definition downloads

In the early days of iPods and MP3 players, consumers were willing to sacrifice sound quality for portability. Now they don't have to. New-generation players offer far greater storage capacity and Internet connections are much faster, making high-definition downloads more feasible and attractive.

Record producer Elliot Mazer said at the electronics show that the music industry's job is to fuel interest in better-quality sound. Mazer is "music czar" for Music Giants, a company that offers high-resolution (24-bit/88kHz) music downloads online. The average price for a high-res download from Music Giants is $15 per album, about 50 percent higher than iTunes.

Boone said CEA research shows consumers are interested in higher quality, "but they just don't know what quality audio is." Musician Joe Miquelon of Kansas City says you don't need to understand bits and sampling rates to recognize great sound. Miquelon, keyboardist for the Elders, a Celtic roots rock band, says a high-quality recording is one where everything is defined and balanced — well-rounded.

"I like it to have bass and treble but not too much of either one. There should also be balance between instruments and voices. Some of the high-end recording is scary, it's so crystal clear."

Robert Bruce, owner of Sound F/X , says recording music in high-definition requires studios to have very high-resolution equipment.