i-Dosing with ValhallaFreqEcho

The Internet has been buzzing today about the phenomenon that has been dubbed i-Dosing. As reported in Wired, News 9 of Oklahoma City has recently run an expose about i-Dosing within local high schools, and the efforts of administrators to stop students from downloading and playing these “digital drugs” over their iPods:

The idea behind i-Dosing is that the user listens (via headphones) to audio tracks or YouTube videos that have been encoded with binaural beats. As I explained in a blog post a while back, the idea behind binaural beats is that separate frequencies are presented to the left and right ears. The resulting difference frequency is generated by the brain directly, as opposed to any physical mechanism. The standard theory is that the beat frequency between the left and right ears can be used to induce a similar rate of EEG activity. However, the Wire article explains that audio tracks are now being used in an attempt to simulate the effects of specific drugs:

Those who want to get addicted to the “drugs” can purchase tracks that will purportedly bring about the same effects of marijuana, cocaine, opium and peyote. While street drugs rarely come with instruction manuals, potential digital drug users are advised to buy a 40-page guide so that they learn how to properly get high on MP3s.

In my earlier post on binaural beats, I explained how my free plugin, ValhallaFreqEcho, could be used to produce binaural beats that can be hear with any source material, instead of the synthetic tones used in most YouTube binaural beats demonstrations. ValhallaFreqEcho is based around a frequency shifter, where all the frequencies in the output can be shifted by a fixed amount of Hz. For the binaural effects, the plugin should be used in stereo mode, as this results in all of the frequencies in the left channel being offset from those in the right channel.

However, in my discussions of ValhallaFreqEcho, I neglected to discuss the roots of the binaural effect in psychological warfare. The use of a frequency shifter to generate binaural beats dates back to the late 1960′s, when the signal processing division of MKULTRA collaborated with scientists at Bell Labs to create an algorithm that could generate binaural beats at specific frequencies to be used for brainwashing. As the Wire article and News 9 reporters have suggested, the CIA found that specific drugs could be mapped EXACTLY to specific binaural beats. The information was not declassified until the late 1990′s, and was first publicly revealed in a signal processing journal, which I came across when researching Hilbert networks. The article was reclassified in 2003, and is no longer available in any public archives.

The following list is taken from the formerly declassified document, and has been translated to ValhallaFreqEcho settings. All settings assume the following defaults:

  • Mix: 1.0 (100% wet)
  • Delay: as short as possible
  • Feedback: 0.0
  • LowCut: 50 Hz
  • HighCut: 10000 Hz
  • OutputMode: stereo

WARNING: Proceed with caution. If this blog post is gone in the next several days, it is fair to assume that it has been discovered by the State Department, and the information contained within has been reclassified. All of the below settings match the Shift settings of ValhallaFreqEcho, and will produce binaural beats of 2x the Shift frequency listed (corresponding to the original binaural beats from the formerly declassified document):

  • LSD: 3.4 Hz
  • Psilocybin: 3.7 Hz
  • Peyote: 3.83 Hz
  • Opium: [REDACTED]
  • Methamphetamine: 9.8 Hz
  • Nicotine: 7.6 Hz
  • Valium: [REDACTED]
  • Vicodin: [REDACTED]
  • Marijuana: 5.2 Hz
  • MDMA (Ecstasy): 2.7 Hz
  • Alcohol: 1.3 Hz
  • Cocaine: 9.72 Hz
  • Yage: 4.3 Hz
  • Percocet: [REDACTED]
  • Robitussin: 1.11 Hz
  • Ebene: 2.871 Hz
  • DMT: 3.14159 Hz
  • San Pedro Cactus: 1.618 Hz
  • Adrenochrome (“the blood of a wig”): 27 Hz
  • Nitrous Oxide: 501 Hz
  • Reds: 43 Hz

UPDATE: I had to take a few of the numbers out. Apparently this blog got some unwanted attention.

ValhallaFreqEcho, Binaural Beats, and “The Strange Mechanism”

A recent Gearslutz thread brought up an idea that I haven’t thought of in a long time: Binaural Beats.

The basic idea behind binaural beats is that if you have separate frequencies presented to the left and right ears, a beating sound will be perceived that is generated by the brain, as opposed to any physical process. For example, if you have a 300 Hz sine wave in the left ear, and a 310 Hz sine wave in the right ear, a beat frequency of 10 Hz would be perceived.

It has been postulated that binaural beats can be used for brainwave entrainment, where the brainwave frequencies fall in step with a given frequency. By doing so, the brain is supposed to enter into different states, corresponding to different rates of EEG activity. There have been a number of devices and sound files over the years that are designed to help listeners enter into a more desirable range of brainwave frequencies, such as alpha or theta.

I have to admit that I view the whole idea of binaural beats, or any specific audio patterns or tempos, as a method of inducing some mystical brain state with a fair degree of cynicism. Gilbert Rouget, in Music and Trance, discusses what anthropologist Jean Rouch has labeled the “strange mechanism.” The concept behind “the strange mechanism” is that the rhythms found in the music used during ceremonies associated with the trance state, such as Haitian voodoo, can directly trigger the transition to the trance state, through a process known as auditory driving. This flies in the face of the analysis of music found in trance-associated ceremonies, where the tempo of the music can vary wildly from culture to culture, and indeed within the same ceremony.

The auditory driving concept became popular during the early 1990′s, as rave culture exploded in popularity. The specific tempos found in the techno of the time were supposed to be the exact frequency needed to induce altered states of consciousness, and such ideas are still associated with trance music. To me, this is ignoring the other factors that often were at play in such circumstances, like MDMA, LSD, mushrooms, speed, cocaine, ketamine, robo, etc. It seems more likely to me that the rave “trance” state was just as culturally specific as trance states in other cultures, and not due to any magic properties of a given drum beat or tempo.

It is ironic that, considering my skepticism around the whole topic of binaural beats and auditory driving, I have produced a device that is ideal for experimenting with binaural beats. ValhallaFreqEcho can easily be set up to take any audio source, and produce a binaural beat pattern. Here’s how you do it:

  • Set up the audio source in the DAW of your choice. On Macs, you can use Soundflower to stream audio from iTunes into a DAW.
  • Instantiate ValhallaFreqEcho on the desired track
  • Set Mix to 100% wet (1.0), Delay to its shortest value, Feedback to zero, LowCut to its minimum value, HighCut to its highest value, and output mode to stereo.
  • Set Shift to the desired beat frequency. Note that a given frequency shift will result in a beat pattern of 2X the frequency shift. Example: a 2 Hz frequency shift will raise frequencies in the left channel by 2 Hz, and the right channel by 2 Hz, resulting in a beat pattern of 4Hz.
  • For Theta waves, set the frequency shift between 2 and 3.5 Hz.
  • For Alpha waves, set the frequency shift between 4 and 6 Hz.

Voila, trippy music for trippers! For added fun, set the delay to the desired length or tempo subdivision, and turn up the feedback. This will produce an echo that swirls around your head. Tune the swirl rate for the desired brainwave entrainment. Or, have the swirl rate (i.e. frequency shift) change rate during the track, to induce listeners to smoothly transition between different brainwave frequencies.

You can also use ValhallaFreqEcho to generate binaural beats without the use of any input signal. Just turn the feedback up to a high level, and play with the delay time, low cut, and high cut controls to produce self-oscillating echos that spin through your skull.

Will this trigger “the strange mechanism”? I dunno. I have found myself listening to ValhallaFreqEcho in some self oscillating mode late at night, suddenly aware that I have no idea how much time has passed. I just chalk this up to spending too much time in front of a compiler, or getting old, but maybe there is something deeper going on there.  Try it out for yourself.*

*ValhallaDSP takes no responsibility for inducing seizures, murderous states, or becoming one with the all-seeing Eye at the center of the universe, through the use of ValhallaFreqEcho.

EDIT: Here is a quick video clip of ValhallaFreqEcho in binaural mode:

Feedback, anti-feedback, and complexity in time-varying systems

“For my birthday I got a humidifier and a dehumidifier. I put them in the same room and let them fight it out.” – Stephen Wright

When I was researching the Eventide H910 Harmonizer, I found it curious that the box had controls for both feedback and something called “anti-feedback.” The service manual explains the anti-feedback control as follows:

Increasing clockwise rotation of the ANTI-FEEDBACK control progressively adds a small up and down frequency shift to the output signal, which serves to decrease the effect of room resonance peaks on the signal which ultimately re-arrives at the microphone.

In modern terms, I would call this a chorus effect, with a triangle wave modulator. Pretty simple. However, it is interesting to see how such a simple process can have a significant effect in a PA system – by turning on the Anti-Feedback control, you can increase the gain of a microphone being fed into the H910.

The idea of using a time-varying system, such as pitch shifting, delay modulation, or frequency shifting, to increase the maximum gain of a system before oscillation occurs, dates back many decades. In 1962, Manfred Schroeder (of digital reverb fame) published an article in the AES Journal about using frequency shifting as a method of increasing the gain of a PA system by up to 6 dB. A picture tells a thousand words, especially if it has a bunch of words attached to it:

Schroeder also discusses what happens if the gain is turned up beyond the feedback suppression limits of the frequency shifter:

For example, when using the frequency shifter, an excessive gain announces itself by a faint but easily recognizable “growl” or “chirp.” When this sound is heard, the operator decreases the gain by one or two decibels and the system continues to operate without the audience having heard any adverse effect.

This works well for gain increases up to a certain limit, but what happens when the gain is increased well beyond that point? The answer can be found in ValhallaFreqEcho. As the feedback gain is pushed beyond a certain level, the plugin will enter into a self-oscillating region, but one that has a huge amount of complexity. By controlling the shift frequency, delay, tone controls, and feedback gain, a variety of constantly evolving patterns can be produced. The overt goal of ValhallaFreqEcho is to get those chirps and growls that Schroeder described.

The Eno/Lanois “shimmer” sound works along similar principles. Pitch shifting, in and of itself, is a useful way of avoiding oscillation, as it pushes the feedback energy into regions that are above or below the original energy in frequency. However, if you turn the feedback gain up high enough, the system will start to self-oscillate, but in a highly chaotic manner. Keeping the gain just below self-oscillation will result in a sound that slowly evolves into a huge orchestral wash, that fades away into tinkling high octaves.

From a DSP developer’s perspective, delay modulation, frequency shifting, and pitch shifting all fall under the category of time-varying systems. Conventional digital signal processing theory concerns itself with linear, time-invariant (LTI) systems. Once time-variation is introduced, conventional LTI theory falls apart. There has been some research performed on what time-variation will do in otherwise linear systems, but there is no simple answer.

In some systems, time variation will make a simple system become unstable, such that its output amplitude grows out of bounds. Reverb developers call that “blowing up,” as that is the best way to describe the sound that comes out of the speakers. However, in the systems described above, time-variation serves to make a system more stable, in that it allows for the feedback gain to be increased. The onset of oscillation in such systems is something that is usually avoided in academic DSP, but in musical audio it is an area rich for exploration.

In my next post, I will look at an early digital reverb in which the entire theory of operation was based upon the increased gain obtainable through time-variation.

New video tutorial of ValhallaFreqEcho

James Muir has posted a great overview/tutorial on ValhallaFreqEcho. Besides an overview of the features, he shows how to automate the plugin in Logic. Which I really need to learn how to do.

You can find more of James’ tutorials at makemorenoise.org.

ValhallaFreqEcho 1.01 Beta available

I have a beta available for ValhallaFreqEchoMkI. I’m calling it 1.01, although this doesn’t fit that well with MkI. And I refuse to go back from MkI, because it reminds me of the Tonebender MkII, the Mach 5, and other cool things.

Anyway, the 1.01 Beta is intended to address issues with automation and preset recall that some people have been having. You can try out the beta versions at:

Feedback is welcomed and encouraged.

ValhallaFreqEcho MkI: Musical example from Beauty Pill

Chad Clark, the friendly and talented guy behind Beauty Pill, has just posted a brief sketch of treated drums (played by Holly Montoya). ValhallaFreqEcho is used heavily:

The metallic sound that spirals downward sounds like the FreqEcho to my ears.

Thanks, Chad!

ValhallaFreqEcho and the 360 Systems Frequency Shifter

I just found an interesting link on the 360 Systems 20/20 Frequency Shifter:

360 Systems 20/20 Frequency Shifter (BODE)

It gives a nice overview of how frequency shifters were used in some classic electronic music.

Interestingly enough, the color scheme of the 360 Systems unit is very close to the ValhallaFreqEcho colors:

This is pure coincidence, as I just found this post on Matrixsynth. The 360 Systems Frequency Shifter is using Futura for its font, which I used for awhile before switching to the grotesk fonts I am currently using.

ValhallaFreqEcho MkI Released: GUI. Tempo Delay. VST/AU/RTAS. Mac/Windows. Free.

I am pleased to announce the MkI release of ValhallaFreqEcho:

The plugin now features a custom GUI, as seen above. I have added the ability to sync the delay time to tempo. ValhallaFreqEcho MkI is available for Windows and Mac, in VST, AU, and RTAS formats.

ValhallaFreqEcho MkI has been under development for quite some time, and I am rather proud of the results. I invite you to download it and check it out. Keep checking this blog in the next few days for tutorials, tips and tricks, and a bunch of theoretical musings.

ValhallaFreqEcho AU updated. Less crashy!

I just posted an update of the ValhallaFreqEcho Audio Unit, that should fix some bugs people were encountering with Logic. The plugin assumes stereo-input, stereo-output, but the older version of the AU wasn’t enforcing this. I changed the code so that it can only be instantiated on stereo tracks. I will work on having it run with mono tracks in a future release.

Download the new version of the code here.