Dolby Headphone (DH) is a new signal-processing scheme that claims to bring surround sound to ordinary headphones. There's lots of information on the Dolby site (http://www.dolby.com/dolbyheadphone/). DH can be applied to existing non-DH soundtracks, in which case it is in the playback electronics or software, or it can be a separate audio track in its own right. I have no access to any electronics or software with DH, but I did check out a copy of Pearl Harbor, which, as far as I know, is the only DVD with a Dolby Headphone soundtrack. (You choose it from the audio setup menu.) I normally listen either with my normal surround system (Denon receiver + B&W and Velodyne speakers) or with the Sony DP-IF5000 digital sound processor (Dolby Digital base unit with special wireless headphones). The Sony unit is pretty good, but at $500 it's impractical for most people. Dolby claims you can use DH with ordinary headphones. To test this, I just plugged in an old, but good, pair of Sony MDR-CD555 headphones into the Denon, set the DVD to DH, and listened. I didn't expect much at all, but was I surprised! The sounds was sensational, and defnitely with a surround effect. In the scene when the planes fly low through the hills approaching Pearl Harbor at the start of the attack, the plane noise seemed to come from behind me and then over my head. I played this scene maybe 5 times with DH, a few times with the "real" surround system, and a few times with the DP-IF5000, and there was no question that DH really works. Dolby is really on to something. DH is mainly being marketed for in-flight entertainment and with portable systems (both laptops and standalone DVD players), but it has a role in the home as well. It's starting to show up in receivers (first in a high-end Denon, as I remember from CES). I hope it shows up in all receivers at some point.