01.16.06
Some Articles on Audio Entrainment, and a Related Reminiscence
I stumbled across a nice selection of articles on various aspects of audio entrainment at the web site of the Center for Neuroacoustic Research. Such information tends to be rather hard to come by, so carpe diem. My only bitch — and it’s a major one — is the stupid web designer made the damn layout too wide even for a 1024×768 screen resolution. Get a clue, will ya? But anyway…well worth the effort.
“Entrainment” is a fascinating phenomenon whereby external stimuli pulsing at frequencies equivalent to specific wave states of the human (and presumably animalian) brain can — and will — cause the brain to sync up. Even more astonishing — to me at least — is the corresponding perceptual/experiential state then ensues in the subject.
This was first done using fields created by electromagnets placed in close proximity to the skull. I first learned of this in a late-1980s article in ye olde Omni magazine detailing the work of one Dr. José M. Delgado — one of those brain researchers whose work crops up in the mind control lit (and for good reason) and who has in fact done Scary Research in that realm for the US government. We’re talking implants and such. Probably his most famous experiment was in the late ’50s, I believe, when he instantly pacified a charging bull simply by pressing the button on a hand-held remote control, triggering a device that had been surgically implanted in the bull’s brain. (Should you doubt such a thing, check out his book Physical Control of the Mind: Toward a Psychocivilized Society (Harper & Row, 1969).)
Somewhere around the time of that Omni article (ca. the late ’80s), it was discovered that sound could achieve the exact same effect. Now, human brain wave states manifest at extremely low frequencies. For example, the Theta state — a dream-like state characterized by intense relaxation and visualization — is right around 6 hertz. Human hearing occupies a range roughly between 20 hertz and 20 kilohertz (and the audibility range of most folks much past their 30s is less than that, even without rock ‘n’ roll or iPods). There ain’t no way you can hear a 6 hertz tone, and ain’t no subwoofer I know of that can even reproduce a tone that low. (Though ya never know what the military might have cooking — but that’s a topic for another day.)
The trick, it turns out, is to use what I call (probably to the intense cringe-afying of the learned) psychoacoustic resonnance frequencies. The principle is simple. If you have two drones tuned just slightly apart — say one at 200 hertz and another at 206 hertz — then the mind perceives what amounts to a harmonic overtone at whatever the interval is between the two tones — in this case, 6 hertz: the magic Theta frequency. Of course, there are other overtones and harmonics as well, some consciously perceived (think Tibetan chants) and some not. But consciously or not, that 6 hertz overtone will work on your brain just as sure as anything.
The New Age and Human Potential folks got ahold of this stuff, and that’s where all those funky “relaxation goggles” in the ’90s came from. You can also find CDs of audio that purport to use audio entrainment to induce instant bliss and make geniuses of babies and whatnot. But despite the New Age marketing hyperbole and the oft (though not always) cracked pots of the mind control conspiracy crowd, the scientific principles are tested and proven.
Around the time I read that Omni article, I was active in the experimental music scene in Chicago. Inspired and most curious, I put together a solo piece, titled Translocation, that sought to use the principles of audio entrainment in a live setting to see what would happen.
Using an old Amiga computer, I was able to lay down a precisely pitched two-tone drone using 200hZ and 206hZ frequencies, with the goal of (hopefully) triggering a Theta state in the audience. This being before affordable digital recording, I taped the drone to 4 track, and used the same deck for playback so I could be (reasonably) confident the tones would be true. This played throughout the piece, and over that I worked in audio collages of similarly-pitched religious trance music from all over the world, as well as live prepared guitar, percussion, and other sonic whatses. I was able to scrabble together a second stereo PA to augment the one the venue already had, and I arrayed the speakers at roughly the four corners of the room. I set the stereo imaging so that instead of being the expected left-right front / left-right back it was more like right-front left-back / left-front right-back. It just seemed like it might sound more interesting.
On stage, I had the 4 track (with some additional collage work laid to the extra two tracks) and a submixer arrangement that allowed me to send two stereo feeds to my dual-PA set-up. I also patched in a couple digital delays, and I was able to control (somewhat) what audio went to which stereo pair using a volume pedal. Basically, it was just a punk-rock “quad” set-up. I patched all my (mostly borrowed) gadgets into my PA spaghetti. I also had a large air duct I’d found in the alley just that day, to which I attached a really fine contact mic sold under the brand name of Drum Bug. Finally, I had my trusty Fender VibroLux amp for the prepared guitar and a couple pedals (though I also split that signal so I could send it to the effects chain feeding the PAs).
(I was poor as shit in them days, so I remain grateful still to the kind folks who did me a solid by lending me all that extra gear. Thanks, guys.)
A side note on the audio collage is definitely warranted here. As I mentioned, I used religious and shamanic trance music from as many different cultures as I could muster from my record collection, everything from Gregorian chants to the obligatory Tibetan chants to stuff from all over Africa, the Middle East, aboriginal America and, hell, all over and back. I recorded the collage over a long night while doing my then-steady DJing gig at a different local club. DJ turntables, as you know, have sliders that allow you to change the pitch of the records so you can better match them when sequeing between them (or playing them at the same time, as is your wont). What amazed me while I was spinning was that I barely had to repitch any of the recordings. It didn’t matter what continent, culture or century these musics were from, they all were in practically the same key. I was even more pleased — if not entirely surprised by that point — to find afterward that the whole collage (i.e. all these different spiritual trance musics) were very closely pitched to the Theta drone I’d created on the Amiga. So close, in fact, that I didn’t have to make any adjustments to bring the different recordings into tonal parity. I had discovered that these ancient traditions of sonically-induced spiritual ecstacy and meditation had keyed in to a basic physiological property of the human brain.
Right. So, the venue — the dearly departed Club Lower Links — happened to be in a windowless basement, and thus with the owner’s kind induglence I was able to produce near-total darkness, except for some very dim, blue area lights for myself and the bartender. Prior to performing, I didn’t explain anything to the audience about what I was (hopefully) up to; I simply suggested that if they were so inclined they should close their eyes and go with the sounds and…see what happens.
The piece went well, combining the planned and/or mostly fixed elements of the drone and the pre-recorded (though semi-mixable) audio collage with completely improvised stuff on the guitar, air duct, and some other crap I had in my kit bag at the time. I myself didn’t experience anything especially different than usual while playing, but of course I was focused on other things like making pretty racket.
What was really amazing and truly special was what happened afterward. The audience literally lined up and, one after another, regaled me with tales of what they had experienced and/or visualized during the piece. Although a few described generally amorphous feelings of “spaciness”, most related a very vivid experience, though the specifics and even general tenor varied wildly. One person, I recall, said she had a sort of memory experience centering on abuse she’d suffered as a child. (I apologized profusely, but she assured me [I think genuinely] that it really had not been traumatic, but more a view from a reflective distance.) The most baroquely spectacular visual experience described to me — which I won’t belabor here — came, ironcally enough, from a person I knew to never have done any drugs to speak of and rarely even drank. I found this most fascinating, and it left me wondering to what extent efforts at more chemically-induced ecstatic/meditative/visonary states actually dull a more innate ability to get to the same place all on our own.
Although I’ve had the great pleasure of a few folks coming up after a set and expressing pleasure at my experimental oscillations — sometimes trancey stuff, sometimes not — I’ve never had an experience before or since, where folks lined up to share the internal experiences prompted (to whatever extent) by my music. It remains a very special memory for me, for which I can only thank the Muse like any responsible artist should.
Some time later, and in a different venue, I attempted a modified repeat of the same basic approach, with additional musicians and more theatrics. But while that piece was reasonably successful in its own right, it definitely did not achieve the entrainment effect the first one apparently did.
Aaaanyway, the articles referenced at the top of this post provide a variety of perspectives and experimental findings on this fascinating — if more-than-slightly scary — phenomenon of audio entrainment. Use your knowledge only for good, Luke.
