Put on headphones, send 200 Hz to your left ear and 210 Hz to your right, and you'll hear something odd: a slow 10 Hz pulse that does not exist in the audio. Your brainstem manufactures it while comparing the two ears. That part is not controversial — it's been documented since 1839, when a Prussian meteorologist named Heinrich Wilhelm Dove first described it.
Everything AFTER that is where the arguing starts. The internet says binaural beats can induce focus, deep sleep, meditation states, and several things no audio file can legally promise. Here's what holds up.
The illusion itself is robust and easy to verify — you can do it in the generator's binaural mode in the next thirty seconds. It only works through headphones (through speakers the tones mix in the air, which makes an ordinary acoustic beat, a different and much less interesting animal). It works best with base tones below about 1000 Hz and beat rates under about 40 Hz. Above those, the effect weakens or vanishes.
Also solid: EEG studies can detect SOME neural response tracking the beat frequency in some conditions. Your auditory system genuinely processes the thing.
The popular claim goes one giant step further: that a 10 Hz beat pushes your whole brain into a 10 Hz "alpha state," and therefore relaxation, focus, or sleep on demand. This is called entrainment, and the evidence for it is a mess.
Some small studies report modest improvements in anxiety or attention. Others find nothing. Meta-analyses — the studies of studies — tend to conclude the same two things: effects, where present, are small, and the research quality is all over the place. Tiny samples, no blinding, inconsistent protocols. Nobody has convincingly shown that the beat frequency specifically causes the claimed state, rather than, say, forty minutes of sitting still with pleasant audio doing what forty minutes of sitting still always does.
Notice what that ISN'T: proof that nothing happens. Listening to a steady, unobtrusive sound genuinely does help many people settle and focus. It's just that plain rain noise performs suspiciously similarly in comparisons. The magic ingredient may simply be "audio that isn't your open-plan office."
No reason not to — it's free and harmless at sensible volumes. Give it a fair shot: headphones on, base around 200 Hz, beat at 10 Hz (the classic "alpha" rate), volume low enough to half-forget, and a solid 15–20 minutes with an actual task in front of you. Then — this is the part everyone skips — try the same session with plain steady noise another day and compare honestly. If binaural wins for you, keep it. You're the only sample size that matters for a $0 intervention.
Skip the tracks promising "instant deep sleep" or anything medical. Anyone selling a specific frequency as a treatment has read less of the research than you just did.