Binaural Beats: Exploring the Effects on Brain and Mind

Human brains typically have a rhythmic pattern. Our physical and emotional well-being is greatly affected by sound. The brain generates a sound experience known as binaural beats. They may have an impact on human psychological processes and brain function.

An illustration of how binaural beats work.

Binaural beats are a phenomenon about which little is known and they are a type of auditory illusion that occurs when sounds with the same intensity and frequency range are transmitted separately to each ear.

For instance, when the 440 Hz tone is supplied to the right ear and the 400 Hz tone is delivered to the left, a 40 Hz beat is perceived, which is regarded as being “inside” the head.

As early as 1839, when H. W. Dove first described the phenomenon, research on binaural beats started. However, because it is a perceptual reaction to stimuli that are artificially produced and do not occur in natural surroundings, research on binaural beats was long abandoned until Oster explained the phenomenon in greater detail.

Additionally, he emphasized how useful binaural beat stimulation may be in real life. Binaural beats have been referred to as digital drugs in many studies.

Digital drugs, also known as binaural beats, are auditory illusions created by listening to two tons of slightly different frequencies, one in each ear. This creates the perception of a third tone and a beat, which is claimed to alter the listener's brain waves and induce specific cognitive or emotional states. However, it is important to note that binaural beats do not contain any actual drugs or psychoactive substances.

Binaural Beats Explained

When you hear two tones - one in each ear - that are slightly different in frequency, your brain processes a beat at the difference of the frequencies. This is called a binaural beat.

Here’s an example: Let’s say you’re listening to a sound in your left ear that’s at a frequency of 132 Hertz (Hz). And in your right ear, you’re listening to a sound that’s at a frequency of 121 Hz. Your brain, however, gradually falls into synchrony with the difference - or 11 Hz. Instead of hearing two different tones, you instead hear a tone at 11 Hz (in addition to the two tones given to each ear). Binaural beats are considered auditory illusions.

For a binaural beat to work, the two tones have to have frequencies less than 1000 Hz, and the difference between the two tones can’t be more than 30 Hz. The tones also have to be listened to separately, one through each ear.

Binaural beats have been explored in music and are sometimes used to help tune instruments, such as pianos and organs. More recently, they have been connected to potential health benefits.

Binaural beats are claimed to induce the same mental state associated with a meditation practice, but much more quickly. In effect, binaural beats are said to:

• Reduce anxiety
• Increase focus and concentration
• Lower stress
• Increase relaxation
• Foster positive moods
• Promote creativity
• Help manage pain

Meditation is the practice of calming the mind and tuning down the number of random thoughts that pass through it. A regular meditation practice has been shown to reduce stress and anxiety, slow down the rate of brain aging and memory loss, promote mental health, and lengthen attention span.

Practicing meditation regularly can be quite difficult, so people have looked to technology for help. Binaural beats between 1 and 30 Hz are alleged to create the same brain wave pattern that one would experience during meditation.

When you listen to a sound with a certain frequency, your brain waves will synchronize with that frequency. The theory is that binaural beats can help create the frequency needed for your brain to create the same waves commonly experienced during a meditation practice. The use of binaural beats in this way is sometimes called brain wave entrainment technology.

Meditation with Binaural Beats

How to Experiment with Binaural Beats

All you need to experiment with binaural beats is a binaural beat audio and a pair of headphones or earbuds. You can easily find audio files of binaural beats online, such as on YouTube or via downloaded audio files to your mp3 player or mobile device.

As mentioned earlier, for a binaural beat to work, the two tones have to have frequencies of less than 1000 Hz, and the difference between the two tones can’t be more than 30 Hz. You can also decide which brain wave fits your desired state. In general:

• Binaural beats in the delta (1 to 4 Hz) range have been associated with deep sleep and relaxation.
• Binaural beats in the theta (4 to 8 Hz) range are linked to REM sleep, reduced anxiety, relaxation, as well as meditative and creative states.
• Binaural beats in the alpha frequencies (8 to 13 Hz) are thought to encourage relaxation, promote positivity, and decrease anxiety.
• Binaural beats in the beta frequencies (14 to 30 Hz) have been linked to increased concentration and alertness, problem-solving, and improved memory.
• Binaural beats of 40 Hz were found to be helpful in enhancing training and learning, according to a 2020 study.

When listening to binaural beats, it’s best to sit in a comfortable place free of distractions. Listening to the binaural beat audio for at least 30 minutes each day in your headphones ensures that the rhythm is entrained (has fallen into synchronization) throughout the brain.

You can experiment with the length of time you listen to the binaural beats to find out what works for you. For example, if you’re experiencing high levels of anxiety or stress, you may want to listen to the audio for a full hour or longer. Remember, you must use headphones for binaural beats to work. You may also want to listen with your eyes closed.

Research and Studies on Binaural Beats

While most studies on the effects of binaural beats have been small, there are several that provide evidence that this auditory illusion does indeed have health benefits, especially related to anxiety, mood, and performance.

An older 2005 controlled study in roughly 100 people about to undergo surgery also found that binaural beats were able to significantly reduce pre-operative anxiety compared to similar audio without the binaural tones and no audio at all. In the study, anxiety levels were cut in half for people who listened to the binaural beat audio.

A 2007 uncontrolled study asked eight adults to listen to a binaural beat CD with delta (1 to 4 Hz) beat frequencies for 60 days straight. The results of the study found that listening to binaural beats for 60 days significantly reduced anxiety and increased the overall quality of life of these participants. Since the study was small, uncontrolled, and relied on patient surveys to collect data, larger studies will be needed to confirm these effects.

One larger 2011 randomized and controlled trial looked at the use of binaural beats in 291 patients admitted to the emergency department at a hospital. The researchers observed significant decreases in anxiety levels in patients exposed to audio with embedded binaural beats compared to those who listened to audio without binaural beats or no audio at all.

A 2019 study combined the effects of binaural beats and autonomous sensory meridian response (ASMR), a phenomenon of a relaxation response to certain audio or visual triggers. It was suggested that the combination of the two were more beneficial than either separately.

However, a 2015 review of studies found that most studies in this area are limited or contradictory, and that there’s evidence of diminishing impact over time. More research is needed to fully understand the potential benefits and how they differ from monaural beats.

Potential Effects on Memory, Psychiatric Disorders, and Brain Activity: An Overview

This study aimed to investigate the effects of binaural beats on memory, psychiatric disorders, and brain activity. Relevant studies have been identified using Web of Science, PubMed, Scopus, and Google Scholar databases.

Memory Functions

Memory functions are linked to fluctuations in brain electrical activity, specifically in theta, alpha, and gamma frequencies, which can impact different aspects of memory. Generally, when binaural beats are stimulated for 5-30 minutes, they attract brain waves to the frequency of the beats.

Research has shown that the effect of binaural beats on long-term memory can vary depending on the frequency used. In general, the beta frequency is more effective in enhancing long-term memory compared to the theta frequency. Several studies contradict the previously mentioned results.

For example, Beauchene conducted a study that found no effect on verbal memory after 5 minutes of binaural beats stimulation with alpha frequency. Similarly, Wahbeh's 2007 study reported opposite results with theta frequency. Also, the literature has revealed significant variability in results, with some studies reporting no significant changes in memory task performance when comparing binaural beats to control conditions.

The discrepancies in findings on the effects of binaural beats can be attributed to variations in study designs, exposure frequencies, and durations. buting to further disparities in results. dictory findings highlight the complexity of their effects.

Cognition

The mental action or process of learning through experience, thought, and the senses is known as cognition. It includes all facets of cognitive abilities, including perception, attention, thought, imagination, intelligence, knowledge formation, memory and working memory, judgment and evaluation, reasoning and computation, problem-solving and decision-making, comprehension, and language production.

Various studies have investigated the effect of binaural beats on cognition. The study by Sharp et al. showed that binaural beats at 40 Hz significantly improved cognition, while at 25 and 100 Hz, the amount of improvement was less. Evidence shows that gamma-frequency binaural beats can enhance cognitive flexibility and improve divergent thinking.

Conversely, research indicates that binaural beats may have no significant effect or even detrimental effects on cognition. A study involving 1,000 participants found that listening to binaural beats during cognitive tasks led to decreased performance scores, suggesting that rather than enhancing cognitive abilities, these auditory stimuli might impair them.

Major Depressive Disorder (MDD)

Major Depressive Disorder (MDD) was predicted to take the top rank by 2030 by the WHO, which placed it as the third most common cause of disease burden globally in 2008. In a randomized controlled trial study on patients with mild to moderate acute phase of depression, it was found that listening to binaural beats with an alpha frequency of 10 Hz for 30 minutes every day for 5 days significantly reduced depression scores.

There are not many studies on the effect of binaural beats on depression, but those present vary in their conclusions. For instance, a study by Daengruan et al. found that MDD patients who received 10 Hz binaural beats in addition to standard treatment showed no significant difference in their depression scores from the control group.

Conversely, some studies have reported that binaural beats can exacerbate feelings of depression. For instance, some participants experienced heightened feelings of depression after listening to theta-frequency binaural beats. This highlights the variability in individual responses to binaural beat therapy.

Anxiety Disorders

A class of extremely common mental health issues known as anxiety disorders can have a crippling effect on everyday functioning and general well-being. ness of binaural beats concluded that binaural beats can be effective for one’s anxiety, attention, memory, and perceived pain, considering different factors, such as the moment of exposure (since the binaural beats are more effective if they are presented before or during the procedure), frequency of the beat (complex-frequency binaural beats have the largest effect), what it is masked with (binaural beats are more effective when they are not masked with music, but there is no difference if they are masked with white or pink noise), and duration (time under exposure does not cause habituation and it should be long enough for obtaining the benefit).

Binaural beats can even be used to reduce anxiety in certain situations (such as preoperative). It has been shown in a study that binaural beats and 432 Hz music can both be effective in reducing preoperative anxiety. It has also been shown in a study that binaural beats can reduce anxiety and pain while undergoing either diagnostic cystoscopy or urethral stent removal.

Several studies have shown the effectiveness of binaural beats listening in reducing anxiety levels and have also proven binaural beats to be more effective than monaural beats in reducing anxiety.

Sleep

Sleep is crucial for one's health and well-being. According to a preliminary study, binaural beats may improve sleep quality. In a study, binaural beats with a 3 Hz delta frequency were used to produce delta activity in the brain.

The potential benefits of binaural beats in promoting improved sleep have been shown by other small research studies. In a study, soccer players who listened to binaural beats between 2 and 8 Hz reported better sleep quality, reduced sleepiness, and easier waking up. Additionally, binaural beats may help in lowering anxiety, in turn promoting better sleep.

However, contradictory findings also exist. some.

Brain Activity (EEG)

The electrical activity of neurons in the brain produces a small voltage signal on the surface of the skin, known as Electroencephalographic (EEG) signals or electrical brain waves. There are four dominant frequency bands of brain waves, each related to distinct brain functions. mation processing.

The binaural beats alter the brain's excitability and can be measured with EEG. Listening to binaural beats with a frequency of 10 Hz can increase delta brain waves in both hemispheres. Since delta waves are linked to deep sleep, it can be concluded that binaural beats have similar effects as meditation, even though people are awake during testing and it is difficult to accurately measure the delta wave that is dominant in deep sleep.

Moreover, the use of binaural beats at alpha frequency resulted in an increase in alpha brain waves, which was particularly evident in the frontal and central regions of the brain. taining a state of relaxation while also enhancing alertness, it is reasonable to assert that binaural beats are effective in boosting these states.

Some studies have shown different results than those previously mentioned. Kim et al. conducted a study that found binaural beats with delta, beta, alpha, and theta frequencies to decrease delta and theta waves, while increasing alpha and beta waves. Additionally, Norhazman conducted a study in 2015 that showed that binaural beats with a 9 Hz frequency increased alpha waves, but decreased beta waves.

Safety and Potential Risks

There are no known side effects to listening to binaural beats, but you’ll want to make sure that the sound level coming through your headphones isn’t set too high.

Prolonged exposure to sounds at or above 85 decibels can cause hearing loss over time. This is roughly the level of noise produced by heavy traffic. Binaural beat technology could be a problem if you have epilepsy, so you should speak with your doctor before trying it. More research is needed to see if there are any side effects to listening to binaural beats over a long period of time.

Binaural Beats: A Potential Tool?

With several human studies to back up the health claims, binaural beats appear to be a potential tool in the fight against anxiety, stress, and negative mental states. Research has found that listening daily to audio with binaural beats may have positive effects on:

• Anxiety
• Memory
• Mood
• Creativity
• Attention

Learning to meditate isn’t always easy. Binaural beats won’t work for everyone, and they aren’t considered a cure for any particular condition.

The Neural Basis and Perception of Binaural Beats

When people are presented with two acoustic signals of slightly different frequencies separately to each ear, the percept of a third tone oscillating at the difference of the two frequencies arises. The percept of this third tone is described as being located in the head, or between the ears. This psychoacoustic phenomenon is called the binaural beat [1].

When, for example, a tone with a frequency of 400 Hz is presented to the right ear and a second tone with a frequency of 420 Hz is presented to the left ear simultaneously, a binaural beat of 20 Hz will occur. There are, however, a number of constraints to the perception of binaural beats.

First, an early study by Licklider et al. [3] demonstrated that the two presented frequencies must be of a maximum of 1000 Hz to elicit a binaural beat. This is due to the fact that the human auditory pathway can only encode sound waves with frequencies up to 1 kHz [4]. Second, binaural beats seem to be best perceived at carrier frequencies-i.e. the frequencies of the two presented tones-of around 400 Hz [5]. Third, Perrott and Nelson [6] demonstrated that the maximum difference for the two tones must be around 30 Hz. Beyond frequency differences of 30 Hz, the two tones are perceived separately instead of eliciting the percept of a binaural beat.

The study by Licklider et al. [3] was the first to characterize the percept of the binaural beat depending on frequency differences in more detail. Up to 20 Hz, the binaural beat is described as a tone fluctuating in loudness, while frequency differences larger than 20 Hz elicit a rough sound. Below a difference of 3 Hz, the binaural beat is perceived as a rotating tone-a sound that appears to rotate in the head from ear to ear [8]. These thresholds are approximate and assumed to vary interindividually [2].

Binaural beats are, as mentioned in the beginning, an illusory phenomenon, which means that its perceptual basis is not the interference of two sound waves, but a result of their combined neural activity elicited in the auditory pathway [10].

The superior olivary complex (SOC), the first locus of the auditory pathway to receive input from both ears and an important structure for sound integration [11], has been identified as the main neuroanatomical structure involved in binaural beat perception [12, 13].

For binaural beat stimulation, the tones are typically presented via headphones to guarantee that exposure to each of the two frequencies is restricted to one ear only [15]. Binaural beats, like monaural beats, fall into the range of auditory modulated tones, which are frequently used in basic acoustic research as well as in clinical diagnostics [19].

Any auditory stimulation using repetitive or modulated tones elicits a specific neural response pattern that can be measured by electroencephalography (EEG) or magnetoencephalography (MEG) [19]. Neural responses are detectable, for example, as auditory steady state responses (ASSRs) [20] or auditory frequency-following responses (FFRs), which both appear immediately after stimulus onset in the form of composite waves [21, 22].

The Brainwave Entrainment Hypothesis

The theoretical basis of psychological research on the effects of binaural beat stimulation is provided by the brainwave entrainment hypothesis [15] which suggests that auditory or visual stimulation at a specific frequency will lead the brain’s electrocortical activity to oscillate at the external signal’s frequency or at its multiples. For binaural beat stimulation, the brainwave entrainment hypothesis was corroborated primarily by empirical studies demonstrating time-locked ASSRs [4, 13, 24].

What makes the possibility of brainwave entrainment (BWE) interesting for psychological research is that specific frequency bands of the human EEG are associated with different physiological and psychological states [33]. The commonly held assumption is that BWE may, thus, be a method to induce specific physiological and psychological states through stimulation within particular frequency bands [15]. Effects of binaural beat stimulation have, consequently, been investigated with respect to a variety of psychological phenomena associated with specific EEG frequency bands, such as aspects of cognitive processing [31, 34, 35], affective states [31, 36, 37], mood [1, 38, 39], pain perception [40, 41], meditation and relaxation [42, 43], mind wandering [44, 45], or creativity [46].

Given that the theoretical basis of the applied studies on effects of binaural beat stimulation is the brainwave entrainment hypothesis [15], the fact that a considerable number of available basic research studies failed to demonstrate sound evidence for BWE [36, 37, 40, 42, 44-46] makes the results of those applied research endeavors highly questionable. There are actually several studies yielding results that are difficult to bring in line with the assumption of brainwave entrainment.

Using 7 Hz (EEG theta frequency) and 16 Hz (beta frequency) binaural beat stimulation, Goodin et al. [5] did not find any differences in average spectral power for the experimental condition compared to a white noise control condition. In the same vein, Gao et al. [50] did not find changes in relative power in response to five minutes of EEG delta, theta, alpha or beta binaural beat stimulation compared to a pink noise condition, and López-Caballero and Escera [51] were also not able to determine effects of binaural beat stimulation on spectral power in any of the major EEG frequency bands.

In recent years, however, a number of neuroscientific studies provided at least partial evidence in favor of the brainwave entrainment hypothesis [e.g., 2, 57, 58]. For example, Schwarz and Taylor [4] found an ASSR with ten minutes of 40 Hz (gamma frequency) binaural beat stimulation in comparison to no-stimulation conditions. Draganova et al. [13] reported similar findings using MEG. Karino et al. [24] demonstrated BWE for stimulation in the delta (1- to 4-Hz range) and theta frequency bands.

Challenges and Heterogeneity in Research

The conflicting findings regarding BWE can be attributed to a number of obvious problems in this field of research. First of all, the operationalization of entrainment effects in the human EEG is diverse, with some researchers considering the presence of time-locked responses in the auditory system (ASSR and FFR, respectively) as indicators of BWE [e.g., 1, 4, 52], while others focus on changes in EEG power measures (oscillatory activity) [5, 50, 51, 55]. Apart from studies looking into EEG measures in the frequency-domain, a number of studies link BWE to the time-domain (event-related potentials, ERPs) [57, 60, 61].

A second limiting factor is that studies in the field tend to use highly heterogeneous study designs [52]. Heterogeneity starts with the study samples, with most studies involving healthy adult populations [e.g., 2, 51, 55, 57], while others examine neurological samples [16, 64]. Another problem is related to the variety of frequencies used for binaural beat stimulation. This is of special importance since it is assumed that different frequency bands differ in their capacity to be entrained [52].

While research on potential psychological effects of binaural beat stimulation is based on the assumption of brainwave entrainment, the empirical basis for this presupposition is open to question given that neuroscientific results on BWE through binaural beat stimulation appear to be largely inconclusive.