Technology: A New World of Sound

Innovative headphones promise an enveloping listening experience

One of the DVD revolution's great leaps forward was encoding Dolby Digital surround sound on each disc--three channels in front, two in the back for atmosphere, plus a subwoofer to provide true-to-life rumbles and thuds. Until that point we had known only two-channel stereo sound, whether from a CD, the TV or a videotape.

But the DVD breakthrough also created problems. One is logistical. Whether you assemble a massive sound system or opt for a simplified "home theater in a box," you have to figure out where to place five speakers plus the subwoofer. Then there's the noise issue. If you...