Anyone have experience with binaural beats?

General Discussion
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@curiositry and I recently did a preliminary experiment to see if we could detect EEG entrainment from binaural beats ( http://www.autodidacts.io/binaural-beat-openbci-eeg-experiment/ ).

We’re going to do some followup experiments, and we would like to gather as much info as we can about how binaural beats are typically used so we can make sure to give them a fair shot at tweaking our brains.

We’re hoping to get input on things like:

  • What beat frequencies have you tried, and what have you found effective?
  • How long a session is required?
  • What are the best carrier frequencies or mixes of beats and other audio?
  • What subjective effects do you notice from binaural beats?
  • What results from commercial binaural beat products?

Have you had experience with binaural beats, or done experiments with them? Let us know!

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From my experience binaural beats has been and so far remained within the realm of pseudo-science. A quick look at a Pubmed results would highlight this feeling as publications are mostly found in journals not specific to neuroelectrophysiology (Front Psychiatry, Int J Cardiol, J Altern Complement Med, Int J Psychophysiol). I don’t mean this to dismiss their work (I haven’t read them) but its certainly a position I’ve repeatedly heard from neuroscientist working on auditory processing and maybe worth putting on the table.

An interesting point of view can be found here:

Yet you might be interested in this piece of literature
http://www.nature.com/ncomms/2014/140902/ncomms5694/full/ncomms5694.html

Cheers !

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@Sebastien_Dery,
Thanks for your post, and welcome to NeuroBB!

As you may have seen from our blog, we found no indication of entrainment in our (very preliminary) binaural beats experiment. It is easy to imagine that there would be a powerful placebo effect from binaural beats, especially when combined with other activities that are known to have neurological and phenomenological effects (such as meditation).

That said, skeptical opinions have to be taken with a grain of salt as well! The lack of articles in appropriate journals could indicate an effect that is under studied, rather than non-existent. (If there were neuroelectrophysiology papers on the topic, but they found no effect, then we’d have reason to believe that there was nothing to investigate.)

In our experiment, we were not even asking what subjective or behavioural results might be had from binaural beats — all we’re trying to determine is whether they entrain “brain waves” in the first place!

Thanks for the link to the paper from Fontolan et. al. I think it’s quite interesting that the mechanisms of information transfer in the context of predictive coding are being discussed in terms of frequency, rather than in terms of lower-level neuron firing activity, or “binary” signals in neural networks.

I’m not at all familiar with the predictive coding literature, so this was a surprise to me.

It seems conceptually simple to unmix B-U higher frequency and T-D lower frequency signals if we think of them as analogous to electrical signals in a wire, but I find it a little daunting to imagine how this relates to the lower level activity (ie, action potentials in neurons) that underlies the oscillations. Crudely put, how does the system know that this action potential is part of some frequency-specific signal, while that one is not? Or are the spectrally-divided signals somehow independent and not a function of neuron firing at all?

To ramble approximately back to the topic, I think one of the most interesting things about binaural beats is that the beat frequency is subjectively audible. Pourquoi? It seems to indicate that the neural signals from the two ears are summed at some point while they are still closely related to the incoming audio waveform, which raises a whole raft of interesting questions about how audio is processed in the brain, and how that relates to what we perceive. Is there is an established understanding of why we hear a binaural beat frequency?

Cheers,
Adam

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@AdamM,
Thanks for your thorough response and kind welcome!
Really enjoy your spirit and work and I certainly hope we’ll get to the bottom of this with interesting results!

You’re absolutely right. Although the tendency to publish (or even have the possibility to publish) negative results is often sadly trumped by the publication industry. EEG have been around for some time now and I can easily imagine enthusiastic researchers taking the journey only to be left disappointed or failing to meet certain standards of science for various reasons (some level of snobbism is probably also expected). Disclaimer: I’m not an expert in auditory processing and thus can only rely on scarce reading here and there. That being said, I certainly think the phenomena exist as a low level sensory processing.

That’s a great question indeed! And I can only draw from my own experience and say I’m not surprise by its subjective nature. As I’m sure you know, flashing light will elicit oscillation-like patterns at the stimulus frequency, otherwise known as frequency-tagging. Interestingly, stimulating with sinusoidal grating will also induce increase power at a narrow-band higher frequency (increasingly associated with low-level processing feedback loops).

Mechanism of Gamma Oscillations

Interestingly the frequency changes from subject to subject. We can discuss more on that as it fall directly on some of my research :smile:

As to the how and why we hear them, I’m sure you read about the importance of timing in inferring direction from sounds. If we assume oscillation are a mechanism of information transmission in the brain, we can hypothesize the frequency difference is interpreted in a similar manner with conduction velocity from different myelination across subject being an important factor in propagation the artifactual perception.

Great question again. The apparent disconnect between action potential and brain oscillation is a hard one to reconcile and certainly a topic of active research. They usually fall in very nice work of computational biology. The field is also increasingly leaving discrete observation towards dynamical system theories to explain the emergence of macro from micro. Naturally we’re also currently limited by the limitations of our model (e.g. including post-synaptic potential with dendrites of varying properties) and our knowledge of anatomical connectivity at the neuron level. Exciting work for sure :smiley:

Cheers,
Sebastien

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Adam, below is a section of an email exchange I had with Isa back in June. Regarding the difference in response seen with isochronic tones vs. binaural beats. My hunch is that you are going to have to look very carefully for binaural effects, since far fewer neurons are involved.

Sorry for the delayed reply. I did checkout your blog post, nice going. I’m sure you’ve seen Chip’s related post using isochronic tones; since you are using his Python code,

EEG Hacker: Brain Got Beats -- Not Yet

I wonder if Chip ever contacted the paper authors and got their insights on what might be going on with his replication? I see that two of the authors email addresses are easily available.

That isochronic entrainment seems like it would engage a fair degree of synchronous neural activity. Hence potentially leading to larger measured signals at the scalp.

Now with the binaural beat situation, that’s not going to cause entrainment at either of the two original tones, because those are just audible sine waves. (Your blog did not state what the left and right ear sine wave frequencies were.) My guess is that the beat detection phenomena (blended perception of left and right), is happening in a much smaller volume of neurons than that engaged with straight entrainment. (Say for example by flashing lights or isochronic tones.) So would be considerably harder to pickup than with entrainment.

Perhaps some kind of ERP, signal averaging over many in-phase events, would be able to pick out the signal from the noise?

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Here’s a related paper, you might have seen this previously, though I did not see it mentioned on your blog post,

Tracking EEG changes in response to alpha and beta binaural beats

by Vernon et al

Abstract

A binaural beat can be produced by presenting two tones of differing frequency, one to each ear. Such auditory stimulation has been suggested to influence behaviour and cognition via the process of cortical entrainment. However, research so far has only shown frequency following responses in the traditional EEG frequency ranges of delta, theta and gamma. Hence a primary aim of this research was to ascertain whether it would be possible to produce clear changes in the EEG in either the alpha or beta frequency ranges. Such changes, if possible, would have a number of important implications as well as potential applications. A secondary goal was to track any observable changes in EEG throughout the entrainment epoch to gain some insight into the nature of the entrainment effects any changes in an effort to identify more effective entrainment regimes. Twenty two healthy participants were recruited and randomly allocated to one of two groups, each of which was exposed to a distinct binaural beat frequency for ten 1-minute epochs. The first group listened to an alpha binaural beat of 10Hz and the second to a beta binaural beat of 20Hz. EEG was recorded from the left and right temporal regions during pre-exposure baselines, stimulus exposure epochs and post-exposure baselines. Analysis of changes in broad-band and narrow-band amplitude, and frequency showed no effect of either binaural beat frequency eliciting a frequency following effect in the EEG. Possible mediating factors are discussed and a number of recommendations are made regarding future studies, exploring entrainment effects from binaural beat presentation.

Full Article: http://stresstherapysolutions.com/uploads/wp-uploads/Vernon.pdf

What the abstract does not state, is that the full article mentions a number of SUCCESSFUL binaural beats EEG studies. Where the EEG changes were seen. So it appears to depend quite a bit on what base tones are used, electrode montage, band being uptrained, whether habituation has occurred, etc.

I think one feature of the commercial binaural beat audio tracks, is that they slowly ‘ramp’ down or up until they reach the desired end frequency. This might have the effect of avoiding the habituation mentioned. Other strategies for avoiding habituation are covered in the paper, including some they tried. Really excellent work on the part of the authors. It motivated me to checkout Vernon’s other publications, some great stuff there.

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@Sebastien_Dery thanks for your reply!

Interesting gamma mechanisms review article — it’s the most detailed general discussion I’ve read on the connection between neuron spiking and a particular frequency of oscillation.

Gamma seems to wear many hats. Among these seem to be its role in coordinated neural assemblies (e.g. Buzsaki and Wang, and also some gap-junction-based modelling by Stuart Hammeroff of microtubule fame); as lower-level, bottom-up signalling that’s associated with perception and modulated or regulated by lower frequency, top-down signals (as in Fontolan); gamma synchony as a neural correlate of consciousness (including in dreaming, when there is little sensory input!); and, finally, as a correlate of long-term meditation practice (for example in http://www.pnas.org/content/101/46/16369.full).

I’m curious in what way, if any, these versions of gamma oscillations are related to each other — or if it’s even meaningful to ask the question!

The effect of a sinosoidal grating is also interesting (and strange!). Is there some correlation between the frequency of the grating and the frequency of the stimulated EEG, or is the grating just an example of a “high amplitude” sensory input? And the EEG frequency changes between subjects?

I’m not sure I understand this correctly — perhaps I don’t know enough about how conduction velocity relates to artifactual perception. What do you mean “across subject”?

It makes sense, though, that the mechanism by which perception of binaural beats emerges would be related to the brain’s sense of auditory direction, especially if the timing of incoming signals from the two ears is compared based on phase differences.

On thinking about this further, the subjective audibility of BB would be expected if what we normally experience as sound is an audio frequency summation from the two ears. But, if this were the case, we would — all else being equal — have a notch in our hearing at the frequency at which the sounds from our two ears cancel each other out when sound was coming from the side (should be around 2.5 KHz), or if audio was otherwise out of phase!

If this is not the case, then it seems like there must be some mechanism that compensates for cancellation of out-of-phase signals, or some other way that we hear binaural beats.

Thanks again for the discussion.

Cheers,
Adam

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Thanks for your replies @wjcroft!

I was not aware of the Vernon paper. I did a very cursory literature search before we started experimenting, but mostly found papers on various psychological and cognitive effects of binaural beats, not on measured entrainment.

It’s interesting that the frequencies that we tried (8 and 17 Hz) are in or close to the range where Vernon et al. and Goodin et al. both looked for and failed to find any entrainment effect.

It looks, from reading both these papers (Goodin’s 2012 PLoS One paper is here: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0034789), like the alpha and beta bands have proved resistant to binaural beat entrainment in several (though not all) other studies as well.

Interestingly, Vernon suggests that future studies should try binaural beat “bursts”, shorter even than their one minute trial segments. This is somewhat contradictory to the feedback we got from many people suggesting that our segments were too short, and we needed to try a longer time in order for entrainment to occur.

I think the next step in our binaural investigation is a more thorough look at the existing literature. I will probably compile a short-form summary of the design and results of previous experiments. Once I’ve got a better understanding of what has been tried so far, and what has worked and what hasn’t, we’ll see if we can come up with a good experiment design that will give the best shot at successful entrainment and hopefully shed some additional light on what makes binaural beats seemingly ineffective in some circumstances and seemingly effective in others.

I think a possibility would be to do an experiment that had ~20 minute segments and included both time periods where attention was focused on the beat audio and where it was focused elsewhere (as in Vernon and Goodin’s tests).

Attentional focus is a variable that does not seem to have been well explored in the binaural beat entrainment literature I’ve seen so far.

Regarding detection and electrode placement: it seems to me that the beat frequency would necessarily be detectable somewhere in the auditory processing areas of the brain. But, this probably would not qualify as supporting the hypothesis of entrainment, since the hypothesis is that there is a FFR that leads to larger-scale changes in frequency and thereby to changes to cognition or consciousness. In principle, I suppose this means that binaural beat research has to make some principled distinction as to what “counts” as entrainment. Probably this distinction could be informed by neurofeedback studies. In practice, though, given that even a “high density” recording like that taken by Goodin et al. did not detect a frequency effect from the binaural beats, it seems likely that surface electrodes are not sensitive and precise enough to detect non-entrainment (if that’s a meaningful term) binaural beat neural activity.

Thanks for your comments, and for bringing your knowledge and experience to the discussion.

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Adam, hi. Also checkout what the various commercial vendors are doing. I believe many of them are using the slow ramping of the beat frequency, in the desired direction. And perhaps once they get it in the range they are looking for, slowly move it around. Again, so as not to habituate.

I would agree with your other commenters, shorter bursts of fixed beat frequencies, could be something the brain would find boring and ‘tune out’.

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Hi William,
We’ll probably approach Munroe and CenterPointe before we do more experimenting and get any suggestions they will provide (though I’m not sure how much of their proprietary techniques they will be willing to divulge). Are there other vendors we should try as well?

Any thoughts about the effect of attention on the beat sound?

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These guys have a modestly priced ($60) Windows program, that lets you build your own session ramps. It also comes with over a hundred sample sessions. Can work with either binaural beats or isochronic tones.

http://www.transparentcorp.com/products/np/

Their free 2 week trial period lets you evaluate before you purchase. The package also incorporates some kind of integration with EEG to measure effects of the entrainment. ‘Biooptimization’ they call it.

I’m not a current user of this, though did play around with it some years ago as the trial. They have a community forum as well.

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My experience with binaural beats were like:

I had good results after about 10 to 15 sessions, ideal of a length of
more than 20 minutes. (If you want to check commercial ones I suggest
Kelley Howell or Robert Monroe).
The quality of the headphones is important, too. Casual Earbuds had less efect than high-level headphones.

It would be interesting if you could reproduce an experiment which
measured cognitive effects of the binaural beats: Volunteers performed
worse when listening to theta waves when they were doing concetration
test.

In the following there is an overview I did elsewhere:

We found that power and phase synchronization were significantly
modulated by beat stimulation not only at temporo-basal, temporo-lateral
and surface sites, but also at mediotemporal sites. Generally, more
significant decreases than increases were observed.
The most prominent power increases were seen after stimulation with
monaural 40-Hz beats. […] Our results suggest that beat stimulation
offers a non-invasive approach for the modulation of intracranial EEG
characteristics.

http://www.ncbi.nlm.nih.gov/pubmed/25345689 .

The impact of binaural beats on creativity.

Results showed that binaural beats, regardless of the presented
frequency, can affect divergent but not convergent thinking. Individuals
with low EBRs mostly benefitted from alpha binaural beat stimulation,
while individuals with high EBRs were unaffected or
even impaired by both alpha and gamma binaural beats. This suggests that
binaural beats, and possibly other forms of cognitive entrainment, are
not suited for a one-size-fits-all approach, and that individual
cognitive-control systems need to be taken into
account when studying cognitive enhancement methods.

http://www.ncbi.nlm.nih.gov/pubmed/24294202 .

Brainwave entrainment for better sleep and post-sleep state of young elite soccer players - a pilot study

Subjective ratings of sleep and awakening quality, sleepiness and
motivational state were significantly improved only in the intervention
group, but did not impact their perceived physical state. In summary,
eight weeks of auditory stimulation with binaural
beats improved perceived sleep quality and the post-sleep state of
athletes, whereas the effect on physical level is assumed to occur in a
time-delayed fashion. It seems to be worthwhile - to further elaborate
long-time effects and consequences on physical
and mental performance.

http://www.ncbi.nlm.nih.gov/pubmed/23862643 .

Binaural beat technology in humans: a pilot study to assess psychologic and physiologic effects.

RESULTS: There was a decrease in trait anxiety (p = 0.004), an increase
in quality of life (p = 0.03), and a decrease in insulin-like growth
factor-1 (p = 0.01) and dopamine (p = 0.02) observed between pre- and
postintervention measurements.

http://www.ncbi.nlm.nih.gov/pubmed/17309374 .

Binaural auditory beats affect vigilance performance and mood.

This study compared the effects of binaural auditory beats in the EEG
beta and EEG theta/delta frequency ranges on mood and on performance of a
vigilance task to investigate their effects on subjective and objective
measures of arousal. Participants (n = 29)
performed a 30-min visual vigilance task on three different days while
listening to pink noise containing simple tones or binaural beats either
in the beta range (16 and 24 Hz) or the theta/delta range (1.5 and 4
Hz). However, participants were kept blind to
the presence of binaural beats to control expectation effects.
Presentation of beta-frequency binaural beats yielded more correct
target detections and fewer false alarms than presentation of
theta/delta frequency binaural beats. In addition, the beta-frequency
beats were associated with less negative mood. Results suggest that the
presentation of binaural auditory beats can affect psychomotor
performance and mood. This technology may have applications for the
control of attention and arousal and the enhancement of
human performance.

http://www.ncbi.nlm.nih.gov/pubmed/9423966 .

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That would be awesome.
I’d encourage you to make a Google Doc so we can collaborate and speed the process.
May I suggest including the number of participants, exclusion criteria and statistics performed in the literature review?

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Good suggestion @Sebastien_Dery. I had started a spreadsheet, but collaborating on a Google doc is much better – could save myself some work too!

Have you used Zotero or some other reference management tool? I’ve started collecting binaural beats references in Zotero, which is an enormous efficiency improvement over handling the publication info manually. Unfortunately, I don’t see a good way to include or collaborate on compiling the particulars of the experiments within Zotero, so a Google spreadsheet is probably still the way to go. I can export from Zotero into .CSV format, which will speed things up.

I’ll send you a PM with the Google doc link once I’ve got it set up.

Anyone else interested in viewing or participating, let me know!

@Pygar, thanks for your report, and the links. If you don’t mind my asking, what type of binaural beats have you used? What kinds of effect did you experience?

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@AdamM
Sorry for not writing for so long, was on vacation.
I have used quite a lot of different binaural beats tracks so far, I started with the brainwave generator and i-doser with some results. I tried Robert Monroes Hemi-Sync and Kelly Howells Tracks “Ecstasy” and “High Focus”.

So far I like Kelly Howells Tracks best and I think they would be best for investigating the effects of binaural beats as they are very high quality and pure sound. Monroe uses several methods to induce altered states of conciousness like breathing and affirmations.

Ecstasy by Kelly Howell: This track is intended to bring the listener in a sensual and erotic state of mind. I’ve listened to the track for 30 times or more. After 10 times I started to experience the effect of feeling heavy and erotic sensations. I think intention and expectation are important factors when using this tracks. This track entrains mostly theta waves which are connected with arousal and good orgasms. But if you didn’t know about the intended effect you also could just feel relaxed or stoned.

High Focus by Kelly Howell: This track is intended to make you focussed. I’ve listened to this track for about 15 times so far. It makes me feel somehow awake (maybe because of expectation, maybe because of entrainment?). After listening I sometimes feel like having had one coffee to much: a little anxious or nervous.

Monroe Products: It took some time until I felt the effects like feeling the body pulsate at the frequency of the binaural beats. During the last times I listened to the tracks I felt like having a bhong of weed… really stoned.

I think the beats work best if you decide to let them work, like an intention. For me it was a skill to “open” to the effects, like riding a surf.

I’m really curious about the results of the study. I wonder if the effects of the binaural beats are really entrainment effects or just operand conditioning due to expectation.
According to my experience it would be interesting if the effects appear during the entrainment session of if they have long-term effects in the brainwave patterns. Like somebody who entrains theta-waves often has more theta-waves in waking life.

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@pygar Thanks for your detailed reply! It would indeed be interesting to find out how much of the subjective effect is due to entrainment and how much is due to expectation and other indirect, cognitively mediated mechanisms. This is a little tricky, since you can’t easily do a blind trial and non-entrainment mechanisms may also cause certain frequencies to become enhanced. (For example, if one is knowingly using an alpha beat intended for relaxation, and working to “open” to the effect, this effort might not only produce a subjective sense of relaxation but also enhanced alpha waves near the target frequency, even without entrainment).

That said, I think the differences between entrainment and non-entrainment effects would probably be visible in the power spectrum around the target frequency. (Entrainment should produce a peak right at the beat frequency, whereas changes due to expectation and intention would more likely produce a less-precise change.)

One more question: in sessions when you’ve noticed effects from binaural beats, how long into the session did you begin to notice an effect?

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After listening to the file for 12 sessions I guess I can feel the effects after 5 or 10 minutes of listening. With more experience maybe quicker.
At times when I use a certain file often even thinking about the file has a subjective effect.

I agree.
Maybe it would be good to experiment with entrainment frequencies which usually don’t appear in a waking EEG, like theta waves and beta waves. An entrainment effect would be easier to detect.

On a subjective level there would be many interesting possibilities e.g. comparing the experiences of users who expect a relaxing file but get a file in the beta-range v/s getting a file in the theta range.

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Hey @pygar thanks for this additional info, and sorry for the slow response. Interesting that you can notice an effect even from thinking about or imagining the audio! I suppose this makes sense, since visualization tends to result in similar brain activity to the actions being visualized. But, it could be very intriguing to measure your EEG while thinking about that BB recording!

We chose 17hz in the BB experiment we did specifically because it was a frequency in which we would not have expected to see increased activity as a result of sitting still with eyes closed. I like your idea of contrasting expectations and beat frequency.

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@AdamM
Using 17 Hz sounds like a good idea. I would love to participate in your experiment, but because of the distance (I’m from Germany) I guess it won’t be possible.
I’m very interested for the results.

Do you also collect the subjective experiences of the participants? Would be interesting…

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@Pygar we’ll keep you posted. So far our experiments have been quite small and fairly informal. We’ll certainly collect subjective reports from participants in our next experiment – that is, when we find time for adequate background research and getting the next experiment organized!

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