Binaural Beats

In 1839, renowned physicist of the time Heinrich Dove stumbled upon and first documented the tantalising phenomenon of binaural beats. He had found that when two tones were played separately to each ear, both varying slightly in pitch from one another, it caused the brain to create a phantom third sound that was equal to the difference between the initial pair of tones. 

Frequency is the property of a tone that we largely hear as pitch; the highest and lowest notes on a piano correspondingly have high and low frequencies. In this instance frequency is concerned with how many times per second air molecules are vibrated by the piano strings in order to produce a sound wave, and it is measured in a unit called hertz (or Hz for short). The more vibrations per second, the higher-pitched a sound we produce.

In the case of binaural beats - where one tone with a frequency of 315 Hz is presented to your left ear, and another tone with a frequency of 325 Hz is presented to your right ear, your brain will pick up on a third frequency pulsing at 10 Hz, the exact difference between the two. 

So, who cares? There’s a third sound and it’s so low-pitched I probably can’t even hear it, you’re thinking. Well, perhaps you’ve heard that by listening to a binaural beat you could induce sleep, deep meditation, or even increase your focus and creativity? Research has elucidated a phenomenon known as the Frequency Following Response (FFR) – whereby your brain begins to follow the binaural beat and resonate in the same rhythmic pattern. The FFR allows us to stimulate the auditory system at very low frequencies, well below the normal range for hearing in humans - which at best can pick up on sounds of around 20 Hz.

Brainwaves aren’t just a name given to eureka moments; they are real patterns of electrical activity associated with different mind-sets or states of consciousness (Tansey, Tansey et al. 1994). These too are measured in frequency. The FFR could hereby potentially entrain our brain, such that the frequency of the binaural beat creates brainwaves of the same frequency. The logic follows that by establishing a repeating brainwave pattern, our cognitive functioning could be influenced. This was thoroughly researched by Dr Gerald Oster in 1973, and his work was published in Scientific American (Oster 1973). It has since paved the way for many further scientific studies, each trying to investigate whether binaural beats could be leveraged for altering or augmenting neural activity.

Anecdotal evidence suggests that binaural beats in the brainwave “Beta” frequency range can improve attention, and that those in the “Alpha” frequency range may increase relaxation. If you jump on Google and type in binaural beats there are suggestions that some can even potentially cause vivid hallucinations (hence why albums such as “Binaural Beats for the Shamanic Journey – by Michael Drake” are illegal in some countries, under the premise of being a ‘gateway drug’).

In a study by Lane & Kasian et al., neither the presenting experimenter nor test subject knew which one of two distinct beats (one in the Beta frequency range and the other in the Delta range) was presented. In fact, the test subjects did not even know they were participating in an experiment to do with binaural beats – they knew only that it was a test of vigilance and mood. The binaural beats were presented continuously during performance of the 30-minute task, which required continuous video monitoring to click on infrequent targets popping up, and mood was assessed both before and after the task using a questionnaire.

The results showed test subjects scored significantly higher in both the vigilance task and subsequent mood assessment when listening to Beta-frequency binaural beats. Participants also made far more errors and yielded higher tiredness scores when listening to Delta beats. 

So, it seems that perhaps the anecdotal evidence could be rooted in some truth. This experiment alone does not definitively show that binaural beats and the FFR are revolutionary shortcuts to intellect and wisdom, however the results do warrant further study of such a tool for practical applications. For example, binaural beats could be used to help people concentrate for long periods of time (air traffic controllers, long haul truckers), or even assist insomnia sufferers in a soothing capacity. More recent research remains inconclusive however, suggesting that their effects on performance or mood may not be any stronger than that of a similar-sounding auditory placebo (Hector D. Orozco Perez 2020) – as such the jury is still out on whether binaural beats can provide the myriad benefits many claim. 

References

Lane, J. D., et al. (1998). "Binaural auditory beats affect vigilance performance and mood." Physiology & Behavior 63(2): 249-252.

Oster, G. (1973). "AUDITORY BEATS IN BRAIN." Scientific American 229(4): 94-102.

Tansey, M. A., et al. (1994). "ELECTROENCEPHALOGRAPHIC CARTOGRAPHY OF CONSCIOUS STATES." International Journal of Neuroscience 77(1-2): 89-98.

Hector D. Orozco Perez et al. (2020). “Binaural Beats through the Auditory Pathway: From Brainstem to Connectivity Patterns.” eNeuro Journal [https://doi.org/10.1523/ENEURO.0232-19.2020]