What are binaural beats?
“Binaural beats” is a term that Gerald Oster, an American biomedical engineer, invented in 1973. It corresponds to an auditory illusion which is generated when you play two different frequencies separately and simultaneously into each ear. A person would hear the difference between the two tones within the brain.
For example, if you have a pair of headphones in each ear, the first one produces a frequency at 200 Hz, and the other produces one at 210 Hz, then the difference between the two being 10 Hz, the binaural beat would be 10 Hz (number of cycles per second).
How do they work?
Listening to binaural beats would then alter the brain rhythms. Your brain starts to resonate at a different frequency, this will induce another state of consciousness.
The purpose of binaural beats is to help the brain reach this frequency more quickly and more easily. The idea is that if you listen with headphones to a sound created by two different frequencies, producing alpha binaural beats, this will cause the brain to create its own alpha waves.
Using binaural beats for sleep
Normally when we are awake, our brain is in a beta state. We are alert. This is the state of consciousness most commonly found in humans. In this state, our brain oscillates at a frequency of between 13 and 30 Hz, which is in the middle of the beta band.
A person’s level of awareness is directly related to the brain wave state, with slower brain waves correlating with a greater level of awareness.
As we sleep, the brain naturally goes into alpha and theta waves, and this is when most of our dreaming occurs, in deep sleep. If you want to induce these waves during waking hours, you can, with a pair of headphones and listening to audio files with binaural beats. Binaural sounds are a good way to tackle sleep issue, treat chronic insomnia and improve overall sleep quality.
The four major states of brain activity are:
- waking consciousness (also called alpha state). Waking consciousness is, as its name suggests, the state in which we are most alert and awake. The body is fully functional, our conscious mind is aware of its surroundings and we are able to carry out your daily activities.
- deep sleep (also called delta state)
- dreaming (also called theta state)
- dreamless sleep (also called spontaneous meditation state)
Which binaural beats to use?
- Delta frequencies (below 4Hz) are associated with deep sleep and deep relaxation state in which the body recuperates and the mind relaxes. In this state, you are not dreaming; you are unconscious. The Delta frequency is the slowest of the frequencies and it signals that you are in a deep, dreamless sleep.
- Theta frequencies (4 to 8 Hz) are linked to REM sleep, relaxation, meditation and creative state. Studies have shown that listening to 2.5 hours of binaural beats (4 Hz) helped subjects to fall asleep faster and sleep longer. As a result, it is common for people to listen to theta frequencies to help them fall asleep, reduce insomnia, or to help them meditate more deeply.
- Alpha frequencies (8 to 13 Hz) are thought to deepen relaxation, and reduce anxiety.
- Beta brainwaves (14 to 30 Hz) are linked to increased concentration and focus, improved memory, and sharpened mental agility. Meditating while your brain is in that relaxed state can help you access your happy thoughts, which can help give you the mental clarity you need to face the day.
- Gamma brain waves(30 Hz and above) are the fastest of brain waves and appear as short bursts of high amplitude, high frequency electrical activity. Gamma waves are believed to be involved in higher mental activity such as information processing and learning.
Do binaural beats actually work
There is a growing body of evidence that suggests that listening to binaural beats can have a beneficial effect on sleep, and in the treatment of anxiety, or pain management. Several studies have showed that listening to binaural beats can have a positive effect for people with mild anxiety. Hence, it seems reasonable to use brain waves therapy and sleep music to treat insomnia.
- In 2001, researchers from University of California, Berkeley found that listening to binaural beats could be helpful in reducing mild anxiety. Participants who listened to binaural beats while resting had lower blood pressure and lower levels of the stress hormone cortisol.
- In 2007, researchers from the National College of Natural Medicine in Oregon evaluated eight study participants who listened to delta waves every day for 60 days. They concluded that binaural beat therapy may exhibit positive effect on self-reported psychologic measures, especially anxiety. You can find the study here.
- An analysis of 22 studies in 2019 found an important correlation between longer exposure to binaural beat tapes and decreased anxiety.
Are there any side effects to listening to binaural beats?
There have been no recorded negative side effects to the use of binaural beats. Be alert to the amount of sound coming from your headphones. Hearing damage may be caused by long-term exposure to loud noises. Avoid situations that require full attention, like driving.
In all cases, if you have any medical conditions, you should speak to your doctor before trying binaural beats therapy.