Binaural beats

Binaural beats are "auditory illusions" created by presenting two slightly different frequencies to each ear separately. The brain perceives a third frequency, called the binaural beat, which corresponds to the difference between the two presented frequencies. For example, if a frequency of 400 Hz is played in one ear and 410 Hz in the other, the brain perceives a binaural beat of 10 Hz (or 10 beats per second).

The effectiveness of binaural beats on inducing hypnosis are inconclusive and controversial. Anecdotally, some subjects report a feeling of zoning out upon hearing the somewhat odd droning pulsing sound of a binaural beat.

A 2017 study suggests that specific frequencies of binaurals can actually aid in theta waves production and could therefore be helpful. In this study, the authors used EEG to measure brain activity in participants who were exposed to a 6-Hz binaural beat. They found that the binaural beat increased general theta rhythm and frontal midline theta activity after 10 minutes of listening. Theta waves are associated with relaxation, sleep, and memory consolidation. Frontal midline theta activity is associated with attention, focus, and self-regulation.

The authors suggest that the effects of the binaural beat on brain activity may be due to entrainment. Entrainment is a process by which two oscillating systems synchronize their oscillations. In this case, the brain's theta rhythm may have synchronized with the 6-Hz binaural beat.

The authors conclude that the findings of this study suggest that binaural beats may have potential for improving cognitive function and reducing stress. However, more research is needed to confirm these findings.

The study used a "6 Hz binaural beat in a 250 Hz carrier tone," which sounds like this: