This topic has always bugged me.
The human brain distinguishes sound direction from 2 factors:
1. Sound latency - meaning the difference in time that the sound arrives in one ear vs the other ear
2. Sound volume - the difference between how loud the sound is in each ear.
I understand latency is mostly used for lower pitch sounds, and volume is used for high pitch sounds.
So, given this, if you're wearing headphones - just regular headphones that take stereo input - you can simulate surround sound pretty accurately. Don't believe me? http://gprime.net/flash.php/soundimmersion - sort of an old link too, from more than 5 years ago i think. Just plug in normal headphones in your PC and close your eyes.
So, basically sound can be recorded in such a way that when listened through headphones it sounds like surround sound. The reason its not, I suppose, is because the same sound can be listened through speakers - which don't need that sort of thing to sound surround sound, they already are physical objects.
But you can take regular stereo sound tracks and apply digital processing to make it sound like virtual surround sound in your headphones. This is what Dolby Headphone processing does, afaik.
Basically, this means that any headphones claiming to be 7.1 or 5.1 that have multiple speakers in them are really just a marketing ploy, since I doubt they give any advantage over regular stereo.
But most importantly - Why are not more manufacturers of portable music players (I'm looking at you Apple and Microsoft) not putting this feature in their devices!?
And why is it so hard to find headphones that are Dolby Headphone certified!
Anyway, rant aside - do any of you happen to know of any good headphones that include this feature? I know there's a few listed on Wiki, and I can certainly google some - and I owned one pair once, some time ago, but it broke, and I've been meaning to find a quality one ever since, so I'm looking for someone who's had some experience.