A free tool from Sophie's Bureau

Sound for focus, rest and sleep.

Pick what the day needs and press Start. Each routine is a short run of tones that moves you from one state to the next: settling before work, opening up for creative thinking, or winding down towards sleep.

Headphones give you binaural beats, a slightly different tone in each ear.

Speakers switch to pulsed tones that work out loud.

No account, and nothing you play leaves this device. Keep the volume low.

The science

What the research says, and how the routines use it.

Find Your Frequency is built on published studies, and the sources are listed at the end so you can read them yourself. Some of the research is well established and some is early, and the notes below say which is which.

Sound	Used in	Why it's here
Delta · 2 Hz	Better sleep, Back to sleep, Physical discomfort	The slowest band, linked with deep sleep. A 3 Hz beat lengthened deep sleep in a small 2018 study
Theta · 4 Hz	Creative work, Short rest, Time feels scarce, Stress, Sleep, Back to sleep	Deep relaxation at the edge of sleep, where images and ideas surface
Theta · 6 Hz	Meditation	Meditators most often show more alpha and theta than at rest, in a 2015 review of 56 EEG studies
Schumann · 7.83 Hz	The settling steps in most routines	A low, even beat for settling in
Alpha · 10 Hz	Focused work day, Complex tasks, Creative work, Quick reset, Meditation	Relaxed, steady attention; part of the research pooled in the 2019 meta-analysis
SMR · 14 Hz	Quick reset	The low end of beta, alert without being busy, to bring you back up after a reset
Beta · 20 Hz	Focused work day	Active concentration. Beta beats improved vigilance and mood in a 1998 study
Gamma · 40 Hz	Complex tasks or strategy	A growing area of research into concentration and memory
Solfeggio tones	Stress, Better sleep, Physical discomfort, Calm background	Steady single tones with a slow pulse, offered for relaxation
Calm tuning · 432 Hz	Build your own	A soft, warm tone for winding down, at the pitch many musicians retune to

How binaural beats work

Play one tone in the left ear and a slightly different one in the right, say 150 Hz and 160 Hz, and the brain hears a third, gentle beat at the difference between them: 10 Hz. The beat is made inside your head, which is why binaural beats need headphones. On speakers, the app plays pulsed tones instead, a single tone that swells and fades at the same rate, so you get a similar rhythm out loud.

What the studies found

A 2019 meta-analysis pooled 22 studies and found a medium, consistent effect of binaural beats on cognition and anxiety, and on how much pain people reported. Listening before a task, or before and during it, did better than listening only during it, and longer exposure helped. That is why the routines open with a settling stretch and run for real lengths instead of five-minute samples.

Listening before you start, as well as during, gave the best results.

An earlier review of auditory beat studies, published in 2015, found several reporting lower anxiety after listening, alongside mixed results for memory and attention. The Stress or overwhelm routine leans on the first of those findings.

Sleep

In a 2018 sleep-laboratory study, people who heard a 3 Hz binaural beat during light sleep reached deep sleep sooner and spent longer in it than on their own baseline night, while a silent control group showed no change. It was a small study of 24 adults over a single night, so treat it as promising rather than settled. The Better sleep routine ends on 2 Hz delta and fades out on its own, with no chime.

Meditation

A 2015 systematic review of 56 EEG studies of mindfulness, with 1,715 people between them, found meditation most often linked with more alpha and theta activity than resting with the eyes closed, though not every study reported it, and no consistent pattern showed up in the other bands. The Meditation routine rests in 6 Hz theta for that reason. It is offered as a steady rhythm to sit with, not a shortcut into the state: the review describes what the brain tends to do in meditation, not what a beat can make it do.

The 3 Hz study above tested people falling asleep at bedtime. Nobody has studied binaural beats for waking in the night, so Back to sleep borrows that study's descent from theta into delta and keeps everything else quiet and dark.

The Schumann resonance

At 7.83 Hz, the Schumann resonance is the lowest natural resonance of the space between the Earth's surface and the ionosphere, kept ringing by lightning around the world. The physicist Winfried Otto Schumann predicted it in 1952. It sits at the top of the theta band, just below alpha, and its low, even beat suits the settling minutes that open most routines.

Solfeggio tones

The Solfeggio tones, from 174 Hz to 963 Hz, come from a modern musical tradition rather than from clinical research. In one small 2018 study, nine adults listened to five minutes of piano music tuned to 528 Hz and, on another day, to 440 Hz; after the 528 Hz music their stress hormone cortisol fell and they reported less tension. Nine people is too few to build claims on, so here they are offered simply as steady, gentle tones that many people find restful. They sound the same on headphones and speakers.

432 Hz

432 Hz is a tuning rather than a Solfeggio tone: the note A pitched about a third of a semitone below the modern standard of 440 Hz. Many musicians retune to it, and plenty of listeners prefer it for calm listening.

The research used whole pieces of music shifted to 432, never a bare tone. In a 2019 pilot, 33 people heard the same music at both tunings on different days; at 432 their heart rate averaged about five beats a minute lower, right at the edge of significance, while blood pressure and breathing did not differ. A 2020 trial with 42 patients waiting for a tooth extraction found that music at either tuning eased anxiety compared with silence, with salivary cortisol lowest in the 432 group. Root canal patients in a 2016 study had lower heart rate and blood pressure with 432 music than without, but there was no 440 group, so that result shows music helps and nothing more.

No large trial exists. The app offers 432 Hz as a soft, warm tone for winding down, and it sounds the same on headphones and speakers.

Still being worked out

Researchers are still working out how the beats have their effect. A 2023 review of 14 EEG studies found the brain's measured response varied from study to study, with methods too different to compare cleanly, and called for more standardised research. The results on mood, focus and pain above don't depend on settling that question.

Sources

Garcia-Argibay, M., Santed, M. A. and Reales, J. M. (2019). Efficacy of binaural auditory beats in cognition, anxiety, and pain perception: a meta-analysis. Psychological Research, 83(2), 357–372. PubMed
Chaieb, L., Wilpert, E. C., Reber, T. P. and Fell, J. (2015). Auditory beat stimulation and its effects on cognition and mood states. Frontiers in Psychiatry, 6, 70. PMC
Jirakittayakorn, N. and Wongsawat, Y. (2018). A novel insight of effects of a 3-Hz binaural beat on sleep stages during sleep. Frontiers in Human Neuroscience, 12, 387. PMC
Lomas, T., Ivtzan, I. and Fu, C. H. Y. (2015). A systematic review of the neurophysiology of mindfulness on EEG oscillations. Neuroscience & Biobehavioral Reviews, 57, 401–410. UEL repository
Lane, J. D., Kasian, S. J., Owens, J. E. and Marsh, G. R. (1998). Binaural auditory beats affect vigilance performance and mood. Physiology & Behavior, 63(2), 249–252. PubMed
Akimoto, K., Hu, A., Yamaguchi, T. and Kobayashi, H. (2018). Effect of 528 Hz music on the endocrine system and autonomic nervous system. Health, 10(9), 1159–1170. SCIRP
Calamassi, D. and Pomponi, G. P. (2019). Music tuned to 440 Hz versus 432 Hz and the health effects: a double-blind cross-over pilot study. Explore, 15(4), 283–290. DOI
Aravena, P. C., Almonacid, C. and Mancilla, M. I. (2020). Effect of music at 432 Hz and 440 Hz on dental anxiety and salivary cortisol levels in patients undergoing tooth extraction: a randomized clinical trial. Journal of Applied Oral Science, 28, e20190601. PMC
Di Nasso, L., Nizzardo, A., Pace, R., Pierleoni, F., Pagavino, G. and Giuliani, V. (2016). Influences of 432 Hz music on the perception of anxiety during endodontic treatment: a randomized controlled clinical trial. Journal of Endodontics, 42(9), 1338–1343. PubMed
Ingendoh, R. M., Posny, E. S. and Heine, A. (2023). Binaural beats to entrain the brain? A systematic review of the effects of binaural beat stimulation on brain oscillatory activity. PLOS ONE, 18(5). PMC

A few sensible notes. Don't listen while driving or operating machinery. If you have epilepsy, a seizure disorder, a pacemaker or a hearing condition, check with your doctor first. Keep the volume low. Find Your Frequency is for relaxation and focus, not a medical treatment, and it is no substitute for seeing a doctor about pain or sleep problems that persist.

Find Your Frequencyby Sophie's Bureau

Go to

The app

Version 2.0.7, 17 October 2026. A 432 Hz tone in Build your own, in its own group after the Solfeggio tones, with a line on what it is used for and what the research shows. The science page sets out the studies behind it.

Version 2.0.6, 10 October 2026. In Build your own, drag the handle beside a step to change the order. On a keyboard, focus the handle and use the up and down arrows.

Version 2.0.5, 10 October 2026. A lighter menu: the section headings lose their dark blocks and keep just the spectrum line.

Version 2.0.4, 10 October 2026. Smoother sound. The noise bed and the soundscapes now loop without a join you can hear, pausing fades out fully before the sound stops, the chime finishes its fade before it ends, and fades that are interrupted carry on from where they were instead of jumping, which could pop in Safari and Firefox.

Version 2.0.3, 9 October 2026. Speakers sound gentler. The pulsed tone now sits higher, where phone and laptop speakers can play it without being turned up, and rests on a warm bed of noise instead of standing bare; the pulse is shallower again. The end chime and the Meditation bell are now a single low note that swells rather than strikes.

Version 2.0.2, 9 October 2026. Three new routines. Quick reset is seven minutes between tasks, down to alpha and back up. Meditation settles you into 6 Hz theta, with a soft bell at the halfway point. Back to sleep is for waking in the night: it starts quietly, goes straight to theta and delta, dims the screen and fades out on its own.

Version 2.0.1, 9 October 2026. The sound now uses the Skin Resonance engine settings. On speakers the pulse is a gentle ripple rather than a flutter, with a softer, darker noise bed underneath; on headphones the tones sit a little further forward of the noise. On phones the menu stays along the bottom while the player is open.

Version 2.0.0, 9 October 2026. A complete redesign. The player now shows the frequency you're hearing in large figures, with a marker on a spectrum from delta to gamma, a travelling wave line and a note for each step. Headphones or speakers switches between binaural beats and pulsed tones. A new Short rest routine joins the eight originals, Better sleep now fades out without a chime, your own routines are saved on your device, a private log keeps your streak, and the science page sets out the research with its sources.

Sophie's Bureau

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