I’m a skeptic and an engineer. For years otherwise reasonable people keep telling me listening to certain specially recorded tapes and CDs puts them in “special” “magical” states that allow them to learn better, sleep better, basically everything better. ‘Hogwash’, I said. ‘Yet another homeopathy like scam’, I said. But now, sitting here reading about a cross-talk problem in an IC, something occured to me.
When you listen to sounds, your ear recieves vibrations and turns them into electrical signals in your brain that travel across synapses (possibly affecting some chemistry). Your brain is capable of discriminating different frequencies(we call this hearing), so the signals must be somehow different based on frequency. Could a consistent frequency audio signal cause electrical cross-talk in the nerves prompting a same-frequency (or harmonic) signal in some other area of the brain prompting unknown effects? Possibly…
So, teeming millions of physicians, neuroscientists, engineers, etc.
What’s the straightdope, is it Hogwash like I think it is, or do the audio brainwave generators such as Holosync have effect other than placebo?
Many years ago I did a bunch of work for a neurobiologist. Fun stuff. It’s amazing how little we actually understand about our brains.
The way you hear is that you have a bunch of itty bitty cells in your ears which act as miniature bandpass filters and each cell only responds to a particular narrow range of frequencies (I’m really glossing over the details here - do a google search for hearing and “hair cells” if you want lots of reading on the details). As you suspected, your brain hears things as a bunch of frequency signals.
Nerve signals in general are kind of funky. Neurons seem to be a bit reluctant to fire at first, then once you get them to go they don’t want to stop. This leads to some weird integration effects within the nerve bundles. If you have a constant frequency signal you are going to experience some of these integrating effects.
Crosstalk does happen quite a bit in nerve bundles. I don’t know how much it happens with hearing but it’s responsible for things like your ears itching when you have a sore throat. The neurobiologist I worked for did some very interesting demonstrations that showed how easily signals can get confused when they are all in the same nerve bundle.
The big question though is what is your brain going to do with all of these signals, and I don’t know that anyone really knows the answer to this one. No one really knows why we like music. Is any sort of repeating sound going to be setting off brainwaves? You betcha. All kinds of nerve cells are going to be firing off, and a whole bunch of different parts of your brain will be activated in response to it. What does this mean? I don’t have a freakin clue. I’m fairly certain that the manufacturers of these fancy shmancy CDs and such don’t have a freakin clue either.
If you want to check for yourself, there’s a free software: SBaGen. As its author explains, “The theory behind binaural beats is that if you apply slightly different frequency sine waves to each ear, a beating affect is created in the brain itself, due to the brain’s internal wiring. If, in the presence of these tones, you relax and let your mind go, your mind will naturally synchronize with the beat frequency. In this way it is possible to tune the frequency of your brain waves to particular frequencies that you have selected, using of the four bands: Delta - deep sleep, Theta - dreaming and intuitive stuff, Alpha - awake, focussed inside, Beta - awake, focussed outside.”. This explanation differs from what I’ve heard elsewhere, which posit their efficacy on skull size and diffraction effects.
Does it work? Mixed firsthand experience.
Disclaimer: The following event happened quite some time back. No endorsement for such activity implied. Late during the comedown from an acid trip, after the visuals had disappeared, I tuned into some binaural beats (<4 Hz) via headphones. Sure enough, I revived some mild visuals while the headphones were worn, and which persisted for about a couple of minutes, after they came off. So, these things do seem to do something. I’ve tried them a few times while sober. A couple of times, I noticed getting alert, especially having visual clarity. Other times, nothing. I’ve never dedicated a serious controlled effort (20+ mins with active concentration, like the software author suggests), so I don’t know about the veracity behind claims of more dramatic states, induced solely via binaural beats.
Sorry to hijack the thread but about a year ago I had heard about a similar device, but instead of a static prerecorded cd or tape of sounds, this one was a true biofeedback version which was able to sense the frequency of your brainwaves and adjust it’s sounds accordingly. I’ve since tried in vain to find a mention of it anywhere. Does anyone know what I’m referring to?