When two tones of slightly different frequencies are played in separate ears simultaneously (usually through headphones), the human brain perceives the creation of a new, third tone, whose frequency is equivalent to the difference between the two tones being played. This auditory illusion is called a binaural beat. For example, if a person hears a tone of 405 Hz in one ear and a tone of 415 Hz in the other, they would be hearing a binaural beat with a frequency of 10 Hz.
Binaural beats are said to provide many of the same benefits as meditation: lower stress, increase focus, aid with sleep and relaxation, boost mood, assist with pain management, and foster creativity. However, these claims are not yet supported by scientific evidence.
The perceptual phenomenon of binaural beats was discovered by Heinrich Wilhelm Dove in 1841 and first described in scientific literature in 1973 .
