I first discovered brainwave entrainment as I was searching for ways to control stress without medication. The idea was so simple that it almost seemed too good to be true… Could the sounds that are specifically designed and the pulsing lights influence our brain activity somehow?
After thoroughly studying the scientific papers, I realized that the research is both intriguing and extremely complicated.
In this article
What Is Brainwave Entrainment?
Have you ever thought of tapping your foot to music? It only takes a moment for you to start moving in time with the beat, right? A similar thing happens to your brain when you listen to rhythmic sounds or watch lights flickering at certain frequencies.
Brainwave entrainment is the natural phenomenon when the brain’s dominant frequency of the electrical signal is aligned with the rhythm imposed by an external stimulus.
Depending on what activity we are involved in, different types of brainwaves can be recorded from our brains:
Delta waves are associated with deep sleep.
The brain produces Theta waves during meditation and when the person is sleepy.
Alpha waves are characteristic of the relaxed, yet awake, state.
Beta brainwaves are associated with active concentration and alertness.
You get the picture, right? By stimulating your brain externally with rhythmic inputs at these frequencies you can actually trick the brain into moving to the next level of functionality, close to the physiological state corresponding to that frequency.
How Binaural Beats Work
Binaural beats are the most common way to get auditory entrainment. They work through a very special auditory trick.
If you are exposed to two slightly different sounds through the right and left ear, e.g. 300 Hz in the left ear and 310 Hz in the right one, no matter what, you won’t hear two distinct sounds. Your brain creates another sound wave that oscillates at the difference between the sounds of two ears, i.e., 10 Hz.
It was Heinrich Wilhelm Dove who found this phenomenon in 1839. The research on its probable impact on consciousness and relaxation began only in the 1970s.
The idea is that your brain synchronizes with a 10 Hz frequency when your brain “hears” a 10 Hz binaural beat. 10 Hz is in the alpha range, so this brain rhythm generation can lead to a relaxed meditative state.
What the Research Actually Shows
This is the turning point of the story.
Going through a series of papers on binaural beats I was puzzled by the unpredictable nature of research results. A systematic review published in 2023 analyzed fourteen experimental studies aimed at measuring brain activity changes occurring during binaural beat sessions.
Only five of these studies provided positive support to the entrainment concept. Discrepant results were reported by eight experiments, while one research presented mixed data.
To some extent, it is discouraging, but there is an important exception to that.
Experimental procedures within these studies were so heterogeneous that the results cannot be directly compared. For example, they varied in carrier frequency, beat frequency, duration, and measurement method. It was like comparing different types of fruit, from apples to oranges and even pineapples.
Recent Research Looks More Promising
A parametric study was performed on 80 volunteers for testing various parameters of binaural beats.
The authors demonstrated that gamma frequency binaural beats (around 40 Hz) combined with a low carrier tone and white noise background do enhance brain attention. In addition, they proved through EEG that the brain entrainment really occurs.
When it comes to the product for relaxation, the research evidence is mostly in favor.
Several independent teams have reported that exposure to binaural beats in the delta (1-4 Hz) and theta (4-8 Hz) ranges lead to lower anxiety and less stress.
A work published in 2024 focused on patients suffering from tinnitus and revealed that 3-month binaural beat treatment in delta, theta, and alpha bands led to a significant decrease in depression and stress, alongside an increase in the quality of life.
Does It Work for Everyone?
The answer is definitely not.
Although someone may feel even euphoric and in a completely different world after listening to binaural beats, the others may show absolute indifference. Effectiveness appears to be dependent on several factors.
Firstly, you must distinguish the beats in order for the method to work. This means you need headphone and good hearing abilities.
Secondly, your psychological condition plays an important role. Study results point out that people who simply lie down with headphones on relax less. Those who actively try to relax and concentrate on their minds obtain better results.
Moreover, some researches showed that different types of noise could influence binaural beats in either a positive or negative way. Pink noise was detrimental when applied together with binaural beats whereas white noise was facilitating the process.
Other Sound-Based Techniques
Binaural beats are not the only option.
Monaural beats are very similar, but the difference is that the two frequencies are already combined before they reach your ears, thus, the brain actually hears a real pulsing sound instead of the imagined one. In addition, since the sound is real, there is no need to use headphones for monaural beats.
Isochronic tones are even simpler in principle. It’s a single tone regularly turned on and off to create a pulsing effect. All you need for this is a speaker, and no fancy equipment is necessary.
Less research has been conducted on isochronic tones relative to binaural beats, nevertheless, because of their ease and availability, they can be a good option.
The Science of Photic Entrainment
Photic stimulation research results appear more reliable than binaural beats ones.
It’s likely to be due to the fact that the visual system is the most dominant one in the way our brains process information. EEG experiments revealed that the use of flickering lights causes the brain to produce corresponding brainwave changes.
Near-infrared pulsed light at 10 Hz was found to greatly stimulate alpha rhythms of the participants. The significant increase in alpha wave activity after LED stimulation suggested that participants had reached a state of relaxation.
Surprisingly, the results stayed for a few minutes after the completion of the procedure.
Connection to Brain Stimulation Technology
The idea of influencing brain activity by means of external stimulation is not limited only to lights and sounds.
One can find also such methods as transcranial direct current stimulation (tDCS) which basically use similar principles but achieve their effects through the application of weak electrical currents rather than sensory stimulation through the senses.
Even though the tDCS method is different from brainwave entrainment techniques, there is some research overlap. For instance, some of these studies indicate that tDCS may modulate brain oscillations and, thus, might be used in combination with entrainment techniques to obtain stronger effects.
Both of these possibilities suffice as non-invasive tools for modulating brain function, mood, and cognition. The main distinction, however, is that while tDCS delivers an electric current through electrodes adherent to the scalp, entrainment makes use of the sensory systems.
What Science Really Tells Us
After closely looking at all the evidence I’ve come to believe that brainwave entrainment, as any other tool, has both positive aspects and limitations.
The scientific community has accepted that brain functioning can be modulated by external rhythmic stimulation. This is not a point of debate.
This field is constantly changing. When researchers not only create more standardized protocols but also deeply understand individual differences in response, clearer answers to the question “who benefits the most from such techniques” will be available.
For now, the scientific evidence can be boiled down to the statement: It’s something real. It’s measurable. Yet it is also highly variable. If the idea speaks to your heart and you come to it from a standpoint of reasonable expectations, then there is indeed a good chance that it will help you unwind and deal with stress.