How do binaural beats work?
According to a 2015 literature review, the tones should be at frequencies lower than 1,000 hertz (Hz) for the brain to detect the binaural beat. The binaural beat that a person perceives is the frequency difference between the waves entering the left and right ear.
For example, if the left ear registers a tone at 200 Hz and the right ear registers one at 210 Hz, the binaural beat is 10 Hz — the difference between the two frequencies.
The findings of a 2018 study suggest that listening to binaural beats for a recommended period can affect a persons subsequent behavior and sleep cycles.
The study authors explain that there are five different categories of frequency pattern:
Delta pattern: Binaural beats in the delta pattern operate at a frequency of 0.5–4 Hz with links to a dreamless sleep. In the study, people who received a delta pattern frequency during sleep entered a deeper stage of sleep, according to electroencephalogram (EEG) brain scan results.
Theta pattern: Practitioners set binaural beats in the theta pattern to a frequency of 4–7 Hz. Theta patterns contribute to improved meditation, creativity, and sleep in the rapid eye movement (REM) phase.
Alpha pattern: Binaural beats in the alpha pattern are at a frequency of 7–13 Hz and may encourage relaxation.
Beta pattern: Binaural beats in the beta pattern are at a frequency of 13–30 Hz. This frequency range may help promote concentration and alertness. However, it can also increase anxiety at the higher end of the range.
Gamma pattern: This frequency pattern accounts for a range of 30–50 Hz. The study authors suggest that these frequencies promote maintenance of arousal while a person is awake.