Audible Illusions
December 13, 2007 5:34 AM   Subscribe

Holophonic sound is an audio recording technique which operates on a principle similar to Holography. The result has been reported to be realistic and life-like three dimensional sounding audio recordings.

You'll need your headphones to get the most out of the three audio demonstrations provided here. Close your eyes, and it's quite an effective illusion.
posted by sambosambo (34 comments total) 15 users marked this as a favorite

This is the way the classic Firesign Theater recordings, for example, should've been made. But as someone mentions on the linked page's comments, the technology of binaural recording has been around for a long time now. I mean, this is just binaural recording, it ain't new. It's great to hear things this way, but of course, it requires playback on headphones, which is why binaural recordings never totally caught on.

Here's a video of some musicians playing, recorded binauraly: note the dummy head at the center of the room: this is typical of binaural recording.
posted by flapjax at midnite at 5:52 AM on December 13, 2007

That's way creepy. I had to stop listening to the haircut one. This is the first time I've ever hated my nice/cheap full sized headphones.

Which reminds me. I've heard rumors about a pair of mics you wear as earbuds to get quick and cheap stereo field head-modeled recording. I want.
posted by loquacious at 5:57 AM on December 13, 2007

loquacious: Take your pick!
posted by flapjax at midnite at 6:00 AM on December 13, 2007

I could swear I found the virtual haircut on MeFi originally, but I can't find it now.

The page formatting is all screwed up for me (probably my workplace firewall) so I can't see the others. :(
posted by DU at 6:01 AM on December 13, 2007

a pair of mics you wear as earbuds

It's usually done with in-ear mics that are connected by by a piece under your chin, kind of like a stethoscope. Otherwise, scratching your ear, and moving one mic relative to the other, would send things flying around the soundscape.

Did record some lectures this way, and you could identify each individual fidgeting and fussing in their respective seats behind you.

And the effect is not just best heard through headphones, it pretty much only works that way.
posted by StickyCarpet at 6:14 AM on December 13, 2007

Problem I've noticed with some binaural recordings is that the soundstage is flipped front-to-back. Depth, left-right, and vertical positioning work, but performers are behind me when they should be in front of me.

Maybe I have screwy ears. But that problem combined with the otherwise very specific sound point placement makes binaural audio a whole lot more annoying than plain old stereo.
posted by ardgedee at 6:19 AM on December 13, 2007

Hasn't Lou Reed been an exponent of binaural audio for years? I recall at least three of his albums recorded binaurally.
posted by the sobsister at 6:34 AM on December 13, 2007

As flapjax notes, this ain't new. I have a couple of CDs from the 90s demonstrating binaural recordings. (Some of them in situations.)
And, yeah, classic Firesign Theater recordings would be great for this technology...though, as they stand, they exploit the headphone environment quite effectively. Ralph Spoilsport in binaural...
posted by Thorzdad at 6:43 AM on December 13, 2007

operates on a principle similar to Holography

In the sense that the relationship between the phases of waveforms adds information. Since the continuous offset of two signals relative to each other is going to require more than the nuyquist minimum number of samples, here is a case for the high resolution audio fidelity that the anti-audiophiles scoff at the need for.

Since mp3s completely discard phase information, I would expect, but do not know for sure, that compression would degrade this aspect of sound before others.
posted by StickyCarpet at 6:47 AM on December 13, 2007

Link doesn't seem to be working for me. Is there an alternate?
posted by Yellowbeard at 6:53 AM on December 13, 2007

When I first read this link this morning I pictured something similar to the Holophoner and immediately began plotting how I'd get one so I could play my Leela a love song.

This is very cool, too, though. There used to be a display of this at MGM Studios--of another haircut. I still remember my Mother's shout of surprise when she heard the clippers come close to her ears.
posted by atayah at 7:17 AM on December 13, 2007 [1 favorite]

I remember hearing on the radio when it was released (1983) that Pink Floyd's The Final Cut was recorded in holophonic sound. When they broadcast it, got all excited and listened and taped it, and I remember thinking WTF??? because I didn't notice any difference between that and other recordings. I guess it's because the dufus radio announcers didn't say to listen to it with headphones.

loquacious: I believe Sony makes microphones that can fit in your ears. I don't know the model number though. Anyone?
posted by strangeguitars at 7:25 AM on December 13, 2007

I can't remember the exact details but Hugo Zuccarelli, the guy who created Holophonics, says that it's a much more elaborate dummy-head-interference-signal voodoo sort of thing, and no-one's licenced to make the system AFIAK, so that's why Holophonics aren't so well-known.

Good ole binaural is great, anyway. Many years ago I bought a $10 pair of light small walkman headphones, replaced the little speakers with $2 Panasonic electret mics, to make a great-performing stealth binaural mic. You can plug them directly into most minidisc portables with a mic in. People think you're just listening to tunes.
posted by Artful Codger at 7:27 AM on December 13, 2007

posted by caddis at 7:54 AM on December 13, 2007

page not found.
posted by Goofyy at 8:02 AM on December 13, 2007

flapjax at midnite: err, thanks. "earbud mic" gets like twenty fucktillion results for cellphone headsets. Different stuff.
posted by loquacious at 8:15 AM on December 13, 2007

Oops. We broke it. This site seems to have the same virtual haircut but in youtube format along with the matchbook demonstration. Let's break that one too.
posted by sambosambo at 8:20 AM on December 13, 2007

StickyCarpet: Since mp3s completely discard phase information, I would expect, but do not know for sure, that compression would degrade this aspect of sound before others.

The samples posted are mp3. You might be thinking of Ogg Vorbis, which does the phase stripping you mentioned. Or so I've heard from the makers of phase analysis software.
posted by Pronoiac at 8:51 AM on December 13, 2007

When the dude started shaking the matchbox behind my head I just about jumped out of my chair. Cool!
posted by Turtles all the way down at 9:02 AM on December 13, 2007

I think Pink Floyd's Final Cut album uses holophonic sounds throughout -- particularly on Get Your Filthy Hands Off My Desert. Same thing with Roger Waters album AMused to Death.
posted by punkfloyd at 9:11 AM on December 13, 2007

Goddam. I've been familiar with the idea of binaural recording for a while, but I never really checked it out. That (excruciatingly scripted) haircut demo just knocked me on my ass. Stunning.

So here's a question: what's the state of the art on dynamically produced binaural soundtracks? I'm thinking video games. First person shooters. Stereo is one thing—it adds a lot to an immersive gaming environment—but let me hear footsteps or ricochet or zombie moans in this kind of field and I will never sleep again.
posted by cortex at 9:33 AM on December 13, 2007

If you go to the itunes store and search for holophonic, you'll get a few nice results. They're short enough that you can listen to most of them without having to actually buy it. There's a hair-dryer track that's pretty neat.
posted by sambosambo at 10:02 AM on December 13, 2007

I remember the first time I listened to Psychic TV's "Dreams Less Sweet" on headphones - there's a bit that must have been recorded in a box that was being buried. It's one of the most unnerving things I've ever heard, especially while listening in the dark.
posted by malocchio at 10:02 AM on December 13, 2007

Listening to Luigi cut my hair kinda reminds me of a pre-assembled Zaireeka.
posted by carsonb at 10:03 AM on December 13, 2007

I swear to god I SAW a matchbox my peripheral vision...
posted by fearfulsymmetry at 10:16 AM on December 13, 2007

cortex: Have you ever gotten to play in a surround sound setup? Friends have sworn by its immersive qualities.
posted by Pronoiac at 10:53 AM on December 13, 2007

A couple times, and enjoyed it, but it's never been practical for me to set it up at home. The idea of containing a proper surround experience in a set of headphones appeals to me greatly.
posted by cortex at 10:59 AM on December 13, 2007

Holophonics is not the same as binaural.

Binaural recording uses the physical placement of microphones as if they were human ears, often in a dummy head, often with fake pinnae (ear cartilage).

Stereo audio content can also be processed to create binaural cues by applying head related transfer functions (HRTF) to existing audio. This works pretty well for most people as it turns out that ears do remarkably similar filtering no matter the person/head/ear.

Holophonics, which requires headphones, is a proprietary process not a microphonic technique. Not everyone has the same experience with it: It was pretty mind-boggling when I heard it a long time ago. The paper bag over the head demo was spooky.

The challenge with Holophonics is that sounds work well only in isolation. Although Pink Floyd's "The Final Cut" used Holophonics throughout, there are no really bitchin'-kewl examples of the process. And they knew that would be true going in.

In about 1991, NASA had produced a wearable HRTF-convolving process. The hardware alone was either ~$15k or ~$35k ( I no longer recall) which located audio cues in stationary space while you turned your head. In studies this had been shown to greatly increase the amount of information a fighter pilot could access before confusion. Imagine a warner buzzer that stays on the nose of the aircraft no matter which way your head is pointed. The problem, as I recall it, was the same as encountered by a virtual reality graphics team about the same period: The computing horsepower at the time was insufficient to keep up with rapid head movements. The solution? Make the helmet/headphones heavier so the user couldn't move their head that fast.
posted by lothar at 11:47 AM on December 13, 2007 [2 favorites]

If you want to do this using your own head, and don't want to spend too much money, Core Sound mics are the way to go.

I have that and a MicroTrack II which makes for amazing recordings. Oh, the twenty-first century!
posted by lupus_yonderboy at 12:49 PM on December 13, 2007

I'm surprised no one has mentioned the (now-absent and possibly gone forever) "Great Moments with Mr. Lincoln" show at Disneyland. The show consisted of a mediocre Ken Burns-type film that led up to the reveal of the Lincoln animatronic (which was pretty good), but the film part was awesomized with the addition of (I think) good headphones that gave the viewer a very immediate experience, with directional sound that included (of course) a haircut, and someone whispering into your left ear very closely. I saw the show a few times, and I could always hear several people in the audience gasp at the whispering part. It was a neat show.

For me, the weirdest/creepiest part of the demo on the linked page wasn't the matchbox being shaken, it was the footsteps of the guy/girl walking around just behind my head. COME OUT AND FACE ME, FUCKER.
posted by Shecky at 1:25 PM on December 13, 2007

Lupus: If you're looking at cheap, you could build your own mics out of capsules, or hit ebay for mics built like those.
posted by Pronoiac at 3:14 PM on December 13, 2007

I'm waiting for v2, which presumably will combine 3D holophonics with beamed, directional, only-you-can-hear-it audio advertising. Still, I probably won't find myself buying stuff at random until v3, which will no doubt feature those elements ramped up into the ultrasonic range... so I won't even hear what I'm hearing... it'll just feel like I'm almost hearing them... in stereo... which must mean that Julian Jaynes, Terence McKenna, my Lincolnian Better Angels, and the infinite wisdom of my intuition all know that I should rent a car from Enterprise rather than Avis, and are trying really hard to tell me so. Even if I don't understand why... just yet.

Sometimes, when you've got your wallet in hand, you just have to go with your instincts.
posted by darth_tedious at 3:42 PM on December 13, 2007

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