Glossary
Binaural beats
Pronunciation: bye-NAW-ral beetsไบนอรัลบีตส์
Binaural beats are an auditory effect in which two slightly different tones, one in each ear, are perceived as a single tone pulsing at the difference between them.
Play a 200 Hz tone into one ear and a 204 Hz tone into the other and you will hear a 4 Hz pulse that exists nowhere in the room — your brain produces it from the mismatch. The effect requires headphones, because it depends on each ear receiving a different signal. It is distinct from acoustic beating, which happens in the air when two close frequencies are played from the same source, and which is what you actually hear in a room full of bowls.
What the claims are, and what holds up: popular audio tracks promise that a given beat frequency drives brainwaves into a matching state. Evidence is mixed. Several studies report modest effects on reported anxiety and on some attention tasks; others find nothing beyond what any steady, pleasant background sound produces. The honest summary is that it is a real perceptual phenomenon with uncertain benefits, not a technology for tuning a brain.
In a KEO session there are no headphones and no recordings, so you will not meet binaural beats in the strict sense. What you will meet is the acoustic cousin: two bowls close in frequency played together, pulsing slowly in open air. People who arrive asking about binaural tracks are usually describing that sensation, and it is worth knowing which one is which when you compare an app to a room.