Yeah, I think it is most worthy thing about UMD which worth an independence topic.

Dolby Headphone track, or other virtual surround headphone track, should be a lot more commonly available, but they are kinda treated like niche gimmick on a few titles everywhere. It's not like everyboby is convenience to get a full multichannel setup.

It seems Dolby Headphone is a little more common on UMD than other physical media, though not by large margin, but at least kinda "exclusive" on some titles. Obviously it's due to nature of portable playback.

It may also be the most preservation-worthy part of UMD.

I guess it was probably a tough call. UMD movies have serious space limitations so having more than one stereo audio track was rare. They weren’t in a position to provide extremely similar audio tracks, like having regular stereo and cheesy surround versions of the same thing.

Two channel surround gimmicks usually produce distracting artifacts, goofy shimmering swirling phasing nonsense. Going only with a surround headphone track seems less correct…however…since there are no UMD consoles, actually watching UMD movies assumes you’re either wearing headphones or suffering with the built in squeakers. In that way using a headphone mix would made sense. I don’t know if anyone would have complained about it or cared one way or the other.

I don’t know about it being “worth preserving” though. UMD sound is not great. I can’t imagine wanting bad dated phase delay nonsense so bad that it would make me prefer something recorded in ATRAC3plus. There is always a newer better cornier fake surround system out there. You’d think if that was your thing that you’d just want a stereo version to run through whatever the latest gadget is.