BACKFIELD IN MOTION

Before I put down for posterity more of the natural principles that govern binaural recordings made for headphones, I must rise to a most unexpected honor--what else may I call it? One of those "10 best" things that in a hundred other situations I blissfully ignore. The 10 Best Gladioli for 1992? The 10 Best Heifers, Mitch Kine, Movies, Soaps, Hockey Players, Goats, the 10 Best Glowworms at the Annual Firefly Competition? Let 'em pass. But, er, ah, ahem, when it comes to BEING a 10-best, the situation is different.

It seems I have been included amongst those considered for the 10 Best Audio Journalists title, as of the present fleeting moment. And this after 45 years! Better late than never. The list comes from a lively West Coast sheet called, suitably, L.A. Audio File, a bulletin for the Los Angeles audio community. It arrived just in time for the Winter CES, a few months back, where I hope it papered tables and floors in all directions. Lovely! I rejoice in fame.

Thank you, Audio File.

On the other hand, and with all due respect, I find myself a bit uncomfortable in that to my mind there are other top-grade journalistic craftsmen here in our Audio stable--my friends, for instance, Len Feldman and Ivan Berger (I could go on and on ...) are in my book definitely CRITICS. Critics in the real meaning of that word. I have a benign suspicion that I was considered because I deal in opinions, whereas my colleagues, as usual, deal with the facts. They don't qualify? Could be, and no offense since the thought is common enough. But the fact is (to give you my opinion) that we all here, in our different ways, are forever evaluating as hard as we can, whether about a Mozart performance or a new-model amp. Thanks again, Audio File. I accept on behalf of the rest of us.

Binaural recording has appeared in this column in long-wave form, recurring every seven to 10 years, hopefully to capture a new generation of Audio readers. No-not just a repeat! As I said in 1982, the boss isn't going to pay me for a repeat run. An update and recap-put it that way. I've uncovered the typed manuscript of the September 1982 binaural summing-up, and I recommend it to all who are intrigued. Notably the gnat that buzzed into my ear, binaurally, whereupon I automatically slapped it and almost broke a finger on the 'phones. The recording of a Florida swamp at night, discussed in that column, was in turn inspired by an earlier piece, in the December 1974 issue, a wavelength before. So it goes. And so we continue in 1992.

My point last month-that a binaural complement to present-day coincident stereo recording, even as little as an inch or so of separation (Rule 3), could give a quite false reading, as to stereo (loudspeaker) effect through the usual monitor 'phones on many a "location" pickup-needs further elucidation.

Once again, via 'phones the difference between mono (no separation of channels) and even as little as an inch of separation (numerous present stereo setups) is astonishing. A real binaural effect, instantly distinguished from mono. All those who use two-channel 'phones for any purpose should take this phenomenon into account. I should add that if you are miking for both loudspeaker and 'phone "stereo"--Walkman-type listening--you have here an interesting new possibility: With coincident separation of the microphone elements, carefully managed, you may find you can optimize your sound both for stereo speakers and for stereo 'phones, and quite differently too. The speakers will not "hear" the very slight phase separations, as is the intent in coincident systems; on the other hand, the 'phones will easily pick up the inch-or-so separation as real binaural sound. Try it. You'll hear what I mean.

To continue, I've discussed the widest and narrowest two-mike spread for binaural-from about 3 feet maximum down to an inch minimum. In later and more versatile experiments, thanks to JVC's headphones with built-in mikes and an easily portable battery recorder, I discovered some startling binaural laws, absolutely inviolable-though newcomers, pro or amateur, are still violating them. All goes to show that you tamper with nature's sonic receptors at your own risk--but if you are creative, maybe to your own advantage. Take Rule 6, which was the very first thing that JVC taught me when I took myself and equipment outdoors and started walking, and it was perhaps the most basic rule of all: You cannot record motion of the recorder, and/or the person with it. There is never any movement at all on your part, as you listen to the 'phone playback later on. How many experimenters have yet to understand this! You start walking, say, down a gravel road, your feet going crunch, crunch, quite audibly. In the flesh, in reality, you move along, easily enough.

We all do it every day. In the playback, even if perfectly reproduced, you stand stock still and raise your feet, one after the other, pounding the same spot. No motion! It's uncanny. The rest of the world moves around or past you; you yourself are rigidly fixed. Not a thing you can do about it.

The rule applies, of course, to other motions--sit down and in playback the chair may move up to meet your bottom, but you are still frozen in place.

You may turn your head (with mikes on it) or turn a dummy head--there is no motion. Again, the outside world moves around, quite persuasively. It seems very realistic, in playback, until something illogical happens.

I quickly ran into-or rather, heard and recorded--a splendid example of this. A jet plane zoomed overhead on a radio beam that seems to lie directly above my house, northeast to southwest. The planes go straight, as the jet trails often show. A curve, even a slight one, is very rare and, even then, slow and slight, gradual not sudden. At 500+ mph? A sudden curve would be unthinkable. Yet as I walked across my lawn, I absentmindedly turned my head, with mikes, to one side to look at something or other, a minor motion having to do with eyes, not ears. Imagine my astonishment to find that in the headphone playback the very realistic jet plane moved sedately overhead, exactly as it had in reality-until suddenly it made an instant right-angle turn. It was the same story: I had moved, but the recording kept me in place and had moved the sonic environment instead.

If you walk past another person, the playback has you stamping up and down in situ, getting nowhere at all, while the other person moves backwards past you. Why? I do not have the expertise to know why. Your ears do not learn these contradictions; they are built-in responses gone haywire in a new sonic environment. Never forget that our receptors were perfected a good many million years ago and are not easily changed-we have to use imagination, as when looking at a black and-white photograph, reading meaning into a partial signal, one dimension entirely absent, all colors absent. Don't think there is any sort of recording, visual or aural, that isn't subject to such curious responses! Stereo too.

I did ponder a lot on Rule 6, the rule of non-movement. Could it be the lack of eye coordination? Normally we tie in the sights and the sounds for a common orientation; this allows us to perceive not only our own motions but the objective motions of everything around us. We correct for jet planes overhead, so that they do not make right-angle turns. And the same for all else. (But what of blind people, especially those who have been sightless from birth and thus have no intelligent response to help them cope?) Yet, as some may remember, I did get a start on this mystery. I deliberately made a binaural recording in which I "talked" my way, via the mikes on my head, straight across my lawn, noting a bulldozer working loudly at some distance, maybe a quarter-mile away, in a specific direction. It was approximately southwest, at an angle off to my right, as I noted on the tape. Then I deliberately made a right-angle turn (and said so), putting the bulldozer suddenly off to the very far right of my walking track.

In the flesh, of course, it was just a bulldozer, still in the same spot, as I turned the corner, down there to the southwest (I live on a hill). The next day I played that tape into my 'phones as I walked the exact same route, coached by the recorded voice. In the flesh, there was no bulldozer-it had departed. All else was the same. Lo! When I turned the same corner, as the tape played, seeing the same scene, there was the bulldozer--and it stayed put as I turned. Bulldozers don't jump right angles either, and this one didn't in playback. Does that begin to answer the riddle presented by Rule 6? There were no camcorders in those days. Maybe somebody with a good one, and two channels of sound, two microphone "ears" to match the visible picture, could devise some further experiments to see if you bring not only the sound (binaural) to your playback 'phones but also a good representation of the simultaneous visuals, Rule 6 can be overcome.

P.S.

Around 1954 I applied for a patent on this idea, that binaural 'phone sound would "project" forward onto a movie screen if you put mikes on your camera. The patent people just laughed and cited preposterous precedents in the 1880s having nothing to do with the case (except legally) to prove me wrong. No patent. But I did hear the sound out front, coming from those people who talked on the screen. Wishful thinking? It probably was. But that's what makes the world go 'round, right?

(by: EDWARD TATNALL CANBY; adapted from Audio magazine, Apr. 1992)

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