Binaural Beats Generator - Delta to Gamma Frequencies

A binaural beat is a perceptual illusion, not a sound that exists in the air. When each ear receives a pure tone at a slightly different frequency — say 200 Hz in the left ear and 210 Hz in the right — the brainstem circuits that compare signals from the two ears produce the sensation of a single tone pulsing at the difference, 10 Hz in this example. The pulse is created inside your auditory system, which is why headphones are essential: through speakers both tones reach both ears, mix acoustically, and you get an ordinary monaural beat instead of a binaural one. This generator gives you direct control over both numbers. The carrier frequency (100 to 1,000 Hz) sets the pitch you consciously hear; carriers in the 200 to 400 Hz range are widely used because the binaural effect is strongest for low-to-mid carriers and weakens above roughly 1,000 Hz. The beat frequency (0.5 to 40 Hz) sets the speed of the perceived pulse and is what the delta, theta, alpha, beta, and gamma presets change. Those names come from EEG research, where brain activity is described in the same frequency bands: delta rhythms dominate deep sleep, theta appears in drowsiness and meditation, alpha in relaxed wakefulness, beta in alert thinking, and gamma in high-level attention. A word of honesty about what binaural beats can and cannot do. The perceptual phenomenon itself is real, well documented, and easy to hear. The stronger claim — that listening to a 6 Hz beat entrains your brain into a theta state and reliably improves memory, sleep, or anxiety — has mixed scientific support: some controlled studies report small effects on relaxation, attention, or perceived stress, while others find none, and meta-analyses generally call the evidence inconsistent. Many people simply find the steady, gentle pulse pleasant to focus or unwind with, much like ambient noise. Treat this tool as an experiment for yourself, not as a medical device, and see the readout line above the controls — left frequency, right frequency, and beat — to know exactly what you are hearing. The practical features round it out: a volume control with gentle fade-in and fade-out so sessions never start with a click, a session timer that stops playback automatically after 15, 30, or 60 minutes (useful when falling asleep), and an offline export that renders 1, 5, or 10 minutes of the exact current configuration to a stereo 16-bit WAV or 192 kbps MP3 file you can load onto any player. Everything is synthesized locally in your browser with the Web Audio API — nothing is uploaded and nothing needs to be installed.