Though they sharing the same surname, binaural beats and binaural audio could not be anymore unalike. Allow me to explain the difference between binaural beats and binaural audio below.
A binaural beat is an auditory illusion perceived when two different pure-tone sine waves, both with frequencies lower than 1500 Hz, with less than a 40 Hz difference between them, are presented to a listener dichotically (one through each ear).
Binaural recording is a method of recording sound that uses two microphones, arranged with the intent to create a 3-D stereo sound sensation for the listener of actually being in the room with the performers or instruments. The result is called binaural audio.
Playback vs. Creation
Binaural beats is a consumptive experience whereas binaural audio recording is a creative experience. Both terms are referring to a similar subject (bi being TWO, aural being related to the ear or the sense of hearing), but they’re not connected by any means.
When you listen to binaural beats, you are not listening to binaural audio.
In binaural beats, the frequencies of the two different pure-tone sine waves are key. Brainwave entrainment happens inside the brain, and is caused by a physiological response. Upon hearing two tones of different frequencies – sent simultaneously to the left and right ears – the brain perceives a third tone based on the mathematical difference between the two frequencies. The brain then follows along at the new frequency and produces brainwaves at the same rate of Hertz (Hz).
For example: if a 200 Hz sound frequency is sent to the left ear, and a 205 Hz to the right ear, the brain will process those two frequencies and perceive a new frequency at 5 Hz.
The brain then follows along at the new frequency (5 Hz), producing brainwaves at the same rate of Hertz (Hz). The technical term for this process is ‘frequency following response’.
HEAR BINAURAL BEATS (HEADPHONES ON)
In binaural recording you MUST have two microphones, arranged with the intent to create a 3-D stereo sound sensation for the listener of actually being in the room with the performers or instruments (see here for a complete list of companies making binaural microphones). This idea of a three dimensional or “internal” form of sound has also translated into useful advancement of technology in many things such as stethoscopes creating “in-head” acoustics and IMAX movies being able to create a three dimensional acoustic experience.
HEAR BINAURAL AUDIO (HEADPHONES ON)
Binaural audio can be used medicinally just like binaural beats.
Many people use binaural beats to focus or sleep. Advocates of binaural beats say the 10Hz sine waves can entrain the brain so that 10Hz alpha-waves in the brain are augmented and thusly induce a meditative state. This is not scientifically proven, but is something that most binaural beats listeners says works.
The same goes for binaural audio and the ASMR movement. ASMR (Autonomous sensory meridian response) is a term used for an experience characterized by a static-like or tingling sensation on the skin that typically begins on the scalp and moves down the back of the neck and upper spine. It has been compared with auditory-tactile synesthesia. ASMR signifies the subjective experience of “low-grade euphoria” characterized by “a combination of positive feelings and a distinct static-like tingling sensation on the skin”. It is most commonly triggered by specific acoustic or visual stimuli, and less commonly by intentional attention control. Again, not scientifically proven to work across all listeners, but for those who experience “tingles” ASMR content captured in binaural audio is the only way they can sleep or focus.
For more info on binaural audio:
From One Ear To Another,
Founder, Hooke Audio