Interactive Binaural Beats & Isochronic Frequency Calculator
Adjust the beat frequency (0.5–100 Hz) and carrier pitch (60–600 Hz) in real time. Use stereo headphones for binaural phase offset or switch to Isochronic for speakers.
Delivery Method
Quick Brainwave Band Presets
Why 40 Hz?
Gamma waves are fast brain rhythms above about 30 Hz. Activity around 40 Hz is linked in EEG research to attention, working memory and binding different sensations into one experience. It is also the frequency at which the auditory system responds most strongly to rhythmic sound: a 1981 study in PNAS by Galambos and colleagues described a clear "40 Hz auditory steady-state response" recorded from the scalp.
That combination, a band associated with concentration and a frequency the brain naturally echoes, has made 40 Hz the most searched-for focus frequency.
The MIT gamma research, explained accurately
Interest exploded after work from Li-Huei Tsai's lab at MIT. In 2016 (Nature) the team showed that flickering light at 40 Hz reduced amyloid plaques in mouse models of Alzheimer's disease. In 2019 (Cell) they reported that 40 Hz sound, delivered as clicks, improved memory and reduced Alzheimer's-related markers in mice, especially when combined with light.
Two things matter here. First, these were animal studies; early human trials are small and ongoing, and no 40 Hz sound is an approved treatment. Second, the studies used sharp clicks or tones pulsing 40 times per second, which is closer to isochronic tones than to binaural beats. That is why this page starts in isochronic mode.
Binaural or isochronic at 40 Hz?
| Binaural 40 Hz | Isochronic 40 Hz | |
|---|---|---|
| Needs headphones | Yes | No |
| How the pulse feels | Subtle, inside the head | Clear, crisp flutter |
| Closest to lab studies | Less | More |
| Best for | Quiet background with headphones | Speakers, stronger rhythm |
Switch between the two in the Brainwaves panel. A carrier around 200 to 250 Hz keeps the tone pleasant over longer sessions.
How to use 40 Hz for focus
- Start at a low volume. A 40 Hz pulse is noticeable, so it should sit just above the background.
- Layer brown noise underneath to soften the edges of the pulse.
- Work in blocks. Start a 25 or 50 minute focus timer and take the break without the tone.
- Compare. Try a few sessions with and without 40 Hz and keep what actually helps your work.
Avoid pulsing sound if you have epilepsy or a seizure disorder. 40 Hz audio is not a treatment for Alzheimer's disease or any other condition.
Frequently asked questions
What does 40 Hz do to the brain?
Rhythmic sound at 40 Hz produces a measurable 40 Hz response in the auditory cortex. Whether this improves focus in everyday life is not well established; many people use it as a concentration aid.
Can 40 Hz sound prevent Alzheimer's?
There is no evidence of that in humans. Promising results come from mouse studies, and human trials are still small and early. Do not use 40 Hz audio as a substitute for medical care.
Should I use binaural or isochronic 40 Hz?
Isochronic tones produce a clearer 40 Hz pulse, work on speakers and are closer to the sounds used in research. Binaural beats are subtler and require headphones.
How long should I listen to 40 Hz?
Research protocols commonly used about an hour a day, but for focus there is no set dose. Start with one work block and keep the volume low.