Binaural Beats, Isochronic Tones, and Solfeggio Frequencies- a No Brainer
Mr. Write dives into Sonic Therapies | Read Time: 9 Min
The mere concept of sound frequencies affecting neural activity, and changing our brain state, or eliciting some form of therapeutic benefit from different wave frequencies, is not only fascinating, it's exciting. The rise in popularity of binaural beats, isochronic tones, and solfeggio frequencies in conversations, stereos, and academic papers has instigated a vast, warranted interest in audio therapies. Some of the new age claims by naturopaths (and the like) regarding these therapies fall on the hyperbolic, and perhaps outside of reality. Though even at the most fundamental and skeptical level, that these are mere pleasant tones that have relaxing consequences due to the "nice sounds" that they are, make them no less worthy of your consideration, contemplation, and potential self-experimentation. There are a compelling amount of scientific studies providing encouraging evidence that something is indeed happening from these audio phenomenons. Something good, even if it's subtle.
Let's begin at the most basic level, sound frequencies. All sounds, even those beyond our capacity to register, are invisible waves expressed in different frequencies. Modern instruments tell us that the sound spectrum ranges from 1 femtohertz (1 fHz or 0.000 000 000 000 001 Hz, the sound of a super massive black hole[1]) with ultrasounds going well past a (1,000,000,000Hz) gigahertz -humans can only hear between, 20Hz-20,000Hz (or 20kHz). 1Hz equals the entire cycle of a sound wave within a second, 10Hz would be ten cycles per second, and so on (Hz= Hertz, the smallest unit of frequency, frequency is in specific reference to speed and time, not volume) [2]. As the Hz increase they become notes (ie: 440Hz= the A note above a middle C key on a piano. Since 1939, 440Hz is also the internationally agreed upon standard frequency that music is tuned to[3]). The combination of these different frequencies, or 'notes,' make chords, and combinations of those make melodies, and so forth until we have music, until we have language.
In 1839 while experimenting with tuning forks, German scientist Heinrich Wilhelm Dove discovered an auditory phenomenon which he named binaural beats [4]. He placed participants in a room with a large tube leading to each ear and rang a tuning fork on either side of their head. The two forks had been calibrated with a marginal difference of frequency. The participants experienced an auditory illusion, a strange pulse within their heads. Inspired by Christiaan Huygen's work, Dove theorized the beats were the result of entrainment [5] (essentially synchronizing) of different sound waves within the brain. There was more than synchronization. The subtle difference in oscillation creates a phantom wave within the brain, a new pulse, or, beat (ergo Binaural Beats). For example, a frequency of 430Hz in the left ear, and 436 Hz in the right generates a 6Hz (Theta) wave.
This discovery percolated a small amount of curiosity over the next century until Dr. Gerald Oster revisited the mysterious illusion with an arsenal of new technology. Utilizing sine wave oscillators (precursors to synths, able to create pure, suspendible sine waves, and dial in frequencies with absolute accuracy- dwarfing the capabilities of tuning forks), headphones (which are able to provide each ear a static environment, avoiding any audio bleeding), and EEGs (to measure neural activity), Oster was able to explore the phenomenons without previous limitations. In his paper Auditory Beats in the Brain[6] Oster finds ground for potential health benefits using these frequencies as a diagnostic tools, and potential aids to various neural ailments due to recorded neural responses observed in listeners. This paper began a renewed interest, and garnished a substantial amount of study, and evidence, supporting benefits in sleep, memory[7], focus[8], anxiety reduction, and relaxation, all as result from exposure to binaural (and monaural beats) over the following decades.
While there are a lot of advantages to explore with binaural beats there is one obvious (though small) disadvantage, which is the necessity of headphones. Another type of audio illusion (also noted in Oster's paper) utilized in sonic therapies is called isochronic tones (or the aforementioned monaural beats). Identical in principle as binaural beats, though unhindered by the need for separation between ears. These frequencies create specific waves by pulsating the same tone through a single, or multiple speakers in stereo, with generally equal benefits as binaural beats.
Finally, we have the Solfeggio Frequencies. Like isochronic tones this sonic therapy uses a single frequency (although different in its absence of a phantom beat), and is also similar in the irrelevance of participants' use of headphones. The Solfeggio scale's origins trace back to the 10 century, to music theorist Guido d'Arezzo. Both Sanskrit and Gregorian Chants are said to use the historic 6 note scale. Modern mathematicians have been able to use the pattern to find another 3 additional notes extending the scale[9]. While there does seem to be some pretty wild claims (from unreliable sources) of the frequencies healing cuts, chakras, etc., [10] there does appear to be merit in more realistic hypotheses (such as sleep aid, and relaxation). A recent study in Tokyo [11] has resulted with evidence showing a notable drop in stress and anxiety when participants were exposed to music tuned to the Solfeggio Scale (specifically 528Hz). Even short exposure to music (five minutes) garnished significant results. A year later, a kindred experiment at the university of Tehran yielded similar, and even more promising results regarding positive hormonal reactions within rat brains[12].
Brainwaves, or, neural oscillations operate in the same fashion (in terms of movement and vibration) as sound waves. With the aid of electroencephalography (EEG, brain scans) techniques, it’s been discovered that different neural activities coincide with specific oscillation frequency bands. These bands are categorized as Delta, Theta, Alpa, Beta and Gamma waves[13], which in regards to neural oscillations are very telling of our brain state. The "phantom beats," or "auditory hallucinations," created by Binaural Beats, and Isochronic Tones can be set to match these frequency bands, and are theorized to influence the brain to these states, entraining the neural oscillations [14] to these frequencies, and encouraging the benefits of these ranges on a subject's current neural activity.
The slowest oscillation, Delta, is between .5-4Hz, measured in the brain during the N3 sleep stage (the deepest stage of sleep, often dreamless[15]), and advanced meditation. Delta waves are the slowest, generated with the least amount of neural activity, accounting for more relaxing benefits. A study by Melisa Gantt in 2003 found that use of both Delta and Theta frequencies lowered anxiety, created better sleep efficiency, and showed considerable promise in aiding many sleep disorders [16]. As with all these states, new age healers, and naturopaths suggest that frequencies tuned to this vibration provide a myriad of wild healing benefits. While these may be true (but are likely not), reaching this state of dreamless sleep does give the body its best opportunity to heal itself, which may account for the far reaching, and subjective claims. Whether or not sound frequencies are attributed to healing itself, they can assist in a calm, relaxing environment that encourages subjects to fall to these restful, and restorative states (even if it's only by encouraging, and inducing sleep).
Resting (if you'll excuse the pun) above Delta, between 4-6.9Hz is the aforementioned Theta state. Within the Theta state our brains pass through both sleep stages N1 (light sleep), and N2 (deep sleep), and is also associated with advanced meditative states. Theta states are believed to inspire creative, and abstract thinking.
Alpha waves are found from 7-12.9Hz. This is the state of mind where dreams enter during REM sleep [17], and where the brain hovers at the beginning of a natural waking state. There is solid ground in claims for the calming tones of Alpha Waves. Multiple studies having patients listen to Alpha Wave Binaural Beats ahead of dental surgeries found a significant drop in pre surgery anxiety before and after the music was introduced [18][19]. Alpha is described as the Twilight state, felt in the fleeting moments before we drift to sleep and as we wake.
We spend the majority of our waking life within the Beta State, stretching from 13 Hz- 39.9Hz. There is a considerable difference in range of frequencies compared to the previous states. The lower end being a more relaxed state of awareness, which is conducive to learning. Deep concentration exists in the high echelons of the frequency.
Finally from 40 Hz onwards we find the fastest waves, Gamma. Information across the brain moves the quickest, it is our highest level of focus and attention. A thorough investigation in 2017 focusing on Gamma Waves introduced by binaural beats yielded fascinating results in memory retention, and emotional response[20]. Another study, investigating brain states achieved by Tibetan Monks while meditating registered a concentrated amount of Gamma rays during "compassion meditations" [21] far beyond the average person's, even those mediating, corroborating levels of relaxed focus.
Outside of hearing damage from listening to music at excessive volumes (especially when using headphones), there is no conceivable, or known evidence, of harm from using any of these tones or frequencies. On the contrary, there is indication with binaural beats that the frequencies don't even need to be audible [6] to have an effect. Today, there are even apps that run binaural beats underneath audio files such as music, or podcasts on your phone to achieve the desired effects. In an ironic twist to concerns of hearing loss or damage, testing in regards to use of binaural beats or isochronic tones for healing tinnitus (a ringing symptom of hearing damage and loss) [22] have yielded significant results with a decrease in painful ringing and associated anxiety.
The benefits of audio therapies has resulted in a niche field of frequency based wellness, sometimes deemed "digital drugs," and more new age, spiritual monikers. While there is substantial evidence for the benefits on depression, pain relief, and decreasing anxiety with binaural beats (and other frequency therapies) this is still quite an unresearched field. Research has been done with generally small sample sizes, short test durations, and subjective questionnaires, which leaves a lot open to interpretation. Many questions still remain, especially in regards to what is causing these effects (actual brain entrainment is debatable and doubtful to many), as well as how long one needs to listen to a piece of audio therapy to yield results (some believe that it's only necessary for a few minutes, others argue between thirty minutes to hours, with a strong argument to be made that more benefits would manifest after prolonged exposure, which few experiments have attempted). Despite the small amount of studies there is a healthy amount of auspicious anecdotal testimonies, and confirmation from self experimenters online in blogs, comments on posts, videos, tweets, as well as forums [23]. It is always important to remain skeptical [24], especially regarding lofty healing or spiritual claims (such as "third eye openings," "trauma healing," "astral-travel-inducing," "chakra cleansing," etc.) by companies trying to capitalize off these audible phenomenons. It is paramount to be cautious, and lead with rationality. There is a fair argument to be made that a lot of the benefits come from the simple, calming effect peaceful ambient music can have on people, and the strength of placebo[25]. If you add those two together you have powerful recipe. As long as you're not shelling out money with unreasonable expectations of what these frequencies can do for you, there is no harm in exploring. Don't let enthusiasm lead you into the irrational, nor skepticism discourage you or worse, room to create a no-cepo [26] effect. Regardless if audio therapies work as branded, they are generally wrapped in pleasant enough music to enjoy the process of exploration.
A recent meta-analysis does reinstate a lot of faith that something is not only happening, but helping[27], and the future looks very promising for future studies and discoveries. It's certain that from unreliable sources the benefits of binaural beats, isochronic tones, and solfeggio frequencies have been hyperbolic, and overzealous- that being said, there is substantial evidence that some objective good is happening. They may not have the powers that some might wish, but they do give you the opportunity to change your moments for the better. Will they cure your depression and anxiety? No. Not immediately. Is deciding to listen to a relaxing piece of music a helpful step forward regardless of any other affect? Certainly. Will binaural beats help you focus as you study or write a paper? Very likely. Beyond the evidence, the tones are pleasant, not distracting, the tracks can be long and eliminate decision fatigue and time wasted on deciding which albums or artists to listen to. Will they open your third eye, and heal all the traumas attached to your chakras? Who knows? Seems unlikely, but without a doubt theta and delta waves can help sooth, and unwind you to a restful, comfortable state before sleeping or while meditating- both activities inarguable in their contribution to good mental hygiene. Should you play some solfeggio frequencies while puttering around your home, doing something mundane like chores, or contemplating while on the couch? Why not? There is a lot of good to come from simply being well intentioned and choosing things that are "good," or "healthy," for you. Experiment, document, share, and enjoy the ambience.
Thanks for joining me for some of my thoughts,
-Mr. Write
*Author's note: This entire piece was written whilst working under the influence of binaural beats. Beyond the references are links to my own binaural beat!
[1] Black Hole Sound Waves
https://science.nasa.gov/science-news/science-at-nasa/2003/09sep_blackholesounds
[2] What are hertz (Hz) in music and technology?Higher HzDecember 4, 2020
https://higherhz.com/what-is-hz-hertz/
[3] A brief history of the establishment of international standard pitch a=440 hertz
Lynn Cavanagh
http://www.wam.hr/sadrzaj/us/Cavanagh_440Hz.pdf
[4] Ueber die durch Magnetisiren des Eisens vermittelst Reibungselektricität inducirten Ströme
H. W. Dove, Annalen der Physik und Chemie, 1841 series 2 vol 54, page 305
[5] https://en.wikipedia.org/wiki/Injection_locking#Entrainment
[6] Auditory Beats in the Brain – Gerald Oster
http://www.brainisohertz.it/p/G%20Oster%20-%20Auditory%20Beats%20in%20the%20Brain.pdf
[7] Potential of binaural beats intervention for improving memory and attention: insights from meta-analysis and systematic review 2023
Sandhya Basu 1 , Bidisha Banerjee 2
https://pubmed.ncbi.nlm.nih.gov/35842538/
[8] A pilot add-on Randomized-Controlled Trial evaluating the effect of binaural beats on study performance, mind-wandering, and core symptoms of adult ADHD patients
Published online by Cambridge University Press: 01 September 2022
F. Malandrone, M. Spadotto, M. Boero, I.F. Bracco and F. Oliva
[9] THE 9 SOLFEGGIO FREQUENCIES AND THEIR BENEFITS Keri Bevan
https://dailydish.co.uk/the-9-solfeggio-frequencies-and-their-benefits/
[10] Solfeggio Frequencies Craig Good
https://skeptoid.com/episodes/4474
[11]Effect of 528 Hz Music on the Endocrine System and Autonomic Nervous System
Kaho Akimoto, Ailing Hu, Takuji Yamaguchi, Hiroyuki Kobayashi 2018
https://www.scirp.org/html/2-8204397_87146.htm
[12] Influence of various intensities of 528 Hz sound-wave in production of testosterone in rat's brain and analysis of behavioral changes
T Babayi Daylari, G H Riazi ,Sh Pooyan, E Fathi,F Hedayati Katouli
https://pubmed.ncbi.nlm.nih.gov/30414050/ 2019
[13] What is the function of the various brainwaves?
Ned Herrmann, Scientific American Dec 22/1997
https://www.scientificamerican.com/article/what-is-the-function-of-t-1997-12-22/
[14] Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system
Michael H. Thaut,Gerald C. McIntosh and Volker Hoemberg 2015 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4344110/
[15] Physiology, Sleep Stages
Aakash K. Patel; Vamsi Reddy; Karlie R. Shumway; John F. Araujo.
[16] Study protocol to support the development of an all-night binaural beat frequency audio program to entrain sleep
Melisa A Gantt
https://pubmed.ncbi.nlm.nih.gov/36779067/
[17] Physiology, Sleep Stages
Aakash K. Patel; Vamsi Reddy; Karlie R. Shumway; John F. Araujo.
[18] Effect of music at 432 Hz and 440 Hz on dental anxiety and salivary cortisol levels in patients undergoing tooth extraction: a randomized clinical trial
Pedro Christian Aravena et al. J Appl Oral Sci. 2020
https://pubmed.ncbi.nlm.nih.gov/32401941/
[19] A prospective, randomised, controlled study examining binaural beat audio and pre-operative anxiety in patients undergoing general anaesthesia for day case surgery
R. Padmanabhan, A. J. Hildreth, D. Laws First published: 07 July 2005
[20] Brain responses to 40-Hz binaural beat and effects on emotion and memory
Nantawachara Jirakittayakorn, Yodchanan Wongsawat2017
[21] Gamma waves in monks
https://www.dalailama.com/news/2007/how-thinking-can-change-the-brain
[22] Binaural sound therapy for tinnitus treatment: A psychometric and neurophysiological evaluation
David I Ibarra-Zarate, Norberto E Naal-Ruiz, Luz María Alonso-Valerdi
https://pubmed.ncbi.nlm.nih.gov/34563804/
[23] Your Brain on Binaural Beats Stephanie Booth
https://www.thirteenthieves.co/blog/your-brain-on-binaural-beats
[24] Binaural Beats: Not Digital Drugsby Brian Dunning
https://skeptoid.com/episodes/4147
[25] Placebo response and effect in randomized clinical trials: meta-research with focus on contextual effects
Sigurlaug H. Hafliðadóttir, Carsten B. Juhl, Sabrina M. Nielsen, Marius Henriksen, an A. Harris, Henning Bliddal, & Robin Christensen
https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-021-05454-8
[26] Nocebo--the opposite of placebo B Kaada. Tidsskr Nor Laegeforen.
https://pubmed.ncbi.nlm.nih.gov/2650014/
[27] Efficacy of binaural auditory beats in cognition, anxiety, and pain perception: a meta-analysis
Miguel Garcia-Argibay, Miguel A. Santed & José M. Reales
https://link.springer.com/article/10.1007/s00426-018-1066-8
Check out my own binaural beat here! Or your favourite streaming service!