Questions, answered.
Signal, translated.

Brainwavest generates rhythmic audio in your browser and plays it back live. Nothing is streamed and nothing is a recording — each session is built from a written specification the moment you press play, which is why the library is 777 sessions but the download is a few kilobytes of instructions rather than hundreds of hours of audio.

Every session is a slow, deliberately uneventful piece of sound designed to hold a steady rhythm while you do something else. It is a wellness tool, not a treatment. See what we do and do not claim.

For most sessions, no — but it depends on the delivery mode. The listening setup row on each session page tells you what its default mode needs. Isochronic and monaural put the rhythm into the sound itself, so they work on speakers. Binaural and poly-rhythmic build the rhythm from the difference between your two ears, so they need stereo headphones to exist at all. On a speaker the two channels mix in the air before they reach you and the effect is simply gone.

There is a second, separate reason a session may want headphones, and it has nothing to do with the beat. Some sessions run a very low carrier — down to 80 Hz — and a phone or laptop speaker barely reproduces that range at all. The rhythm is not lost, but the session is close to inaudible, so those are marked headphones recommended even when the mode itself is speaker-safe.

The player marks any mode that needs headphones, so you never have to remember which is which. If you are on speakers, stay on the mode the session ships with.

Session length is the row on the spec table, and sessions run from 3 to 95 minutes. Each is designed as a whole — the beat moves across the session on a planned path, so a 40-minute session is not a 10-minute session repeated four times. Finishing matters more than volume.

Be sceptical of anyone who promises you a specific feeling on a specific schedule. What most people report is subtle and takes several sessions to distinguish from ordinary settling-down. If you notice nothing, that is a completely ordinary outcome and it is covered honestly in does this actually work.

Work and sleep, yes — most of the catalog is built to be background. Focus sessions in particular are meant to run underneath something else.

Never while driving or operating machinery. Do not use rhythmic audio in any situation where becoming drowsy or inattentive would be dangerous. Full guidance is on the safety page.

Quiet. Start lower than feels right and raise it only if you cannot hear the texture. These sessions are meant to sit at or below the level of a conversation in the next room — there is no benefit to loudness, and long exposure at high volume carries the same hearing risk as any other audio.

A limiter sits at the very end of the audio chain as a safety net against unexpected peaks. It is a backstop, not a license to turn it up.

Yes. Speak to a clinician first if you have epilepsy, a seizure history or known photosensitivity; if you are pregnant; if you have a heart condition or a pacemaker; or if you have a neurological or psychiatric condition or are being treated for one.

Brainwavest is intended for adults and has not been evaluated for children. Stop immediately if you feel discomfort, headache, nausea or disorientation. The full list is on the safety page.

Hertz — the number of times something repeats per second. 10 Hz means ten times a second.

It appears twice on a session page and the two uses are completely different sizes. The carrier is measured in hundreds of hertz and is the pitch you actually hear. The beat is measured in single hertz and is the slow pulse riding on top of it. Confusing the two is the single most common misreading of these numbers.

The audible tone — the pitch you hear. Across the catalog carriers run from 80 Hz (a low hum) to 963 Hz (a clear high tone).

The carrier is not the point of the session; it is the thing the rhythm is carried on, which is where the name comes from. Two sessions with identical rhythms can sound completely different because one sits low and one sits high, so the carrier is mostly a question of what you find comfortable to listen to for an hour.

The rhythm, and where it travels. Beat start is the pulse rate at the beginning of the session; beat target is where it arrives by the end. A session listed as 10 Hz to 2 Hz begins pulsing ten times a second and slows to twice a second.

The reason sessions move rather than sitting still is that a rhythm you are already close to is easier to follow than one you are dropped into. A sleep session that started at its destination would be asking you to be nearly asleep before it began.

Some sessions have waypoints in between and do not travel in a straight line — see why the band changes mid-session.

A picture of the embedded pulse over time. The horizontal axis is the session, the vertical axis is the modulation rate in hertz, and the line is the path the audio engine will follow. The colored zones mark the named frequency ranges the pulse moves through, while the caption explains how that movement is intended to shape the listening experience.

It is drawn from the same waypoints that drive the audio, including intermediate turns and steady holds—not sketched to look plausible. It is also not an EEG reading and does not promise that your brain activity will follow the line. The chart describes the generated signal; listening responses vary.

How long the beat takes to travel from its start to its target. A 5-minute ramp means the pulse spends five minutes gliding to its destination and then holds there for the rest of the session.

Ramps in the catalog run from immediate to about 76 minutes. Long ramps belong to sleep and recovery sessions, where the whole design is to be so gradual you never notice a transition; short ramps belong to focus sessions, where you want to arrive and get on with it.

The part after the transition, when the generated pulse has reached the session's advertised beat target and stays there. A 34-minute session with a 20-minute ramp has a 14-minute designed target hold.

You can begin with the full journey or start directly at that target. In the player, Go to target skips the remaining transition, the timeline lets you revisit any point, the plus-time choices prolong listening from now, and Open removes the scheduled ending until you stop the session yourself.

How pronounced the pulse is, from 0 to 1. At 0.5 the sound dips to half volume on each beat and the rhythm is a gentle swell. At 0.98 it drops almost to silence between beats and the rhythm is unmistakable.

Catalog values run from 0.5 to 0.98. Sleep and calm sessions sit high — a strong, slow pulse is easy to sink into — while focus sessions sit lower, because a rhythm that insistent becomes the thing you are paying attention to instead of your work.

The shape of a single pulse — how the sound rises and falls each time it beats. Same rhythm, different feel. This is the row that most determines whether a session sounds soft or percussive.

Square wave switches abruptly on and off: the sharpest, most audible pulse. Trapezoidal rises, holds, then falls — clear but not clicky. Raised cosine and sine envelope swell and fade smoothly with no corners at all. Smooth bell peaks in the middle and tapers both sides. Sigmoidal eases in and out with a firmer middle, sitting between smooth and square.

The envelope row only appears on sessions whose delivery actually uses one. Isochronic and poly-rhythmic shape a pulse; binaural and monaural build their beat from two tones drifting against each other, so there is no pulse shape to choose, and phase-amplitude coupling produces its shape from one rhythm nested inside another.

How much of each beat the pulse is actually sounding. At 50% — the catalog default — the pulse and the gap are equal, and the rhythm is an even throb. At 25% the sound is on for a quarter of each beat and off for the rest, which is sparse and metronomic. At 90% it is very nearly continuous, with only a slight waver.

It changes loudness as well as character: a 10% duty measures about 7 dB quieter than a 50% one, simply because there is less sound. Like the envelope, this row only appears on sessions whose delivery mode shapes a pulse.

The fast rhythm inside the slow one, on phase-amplitude coupled sessions. The slow beat does not switch the tone on and off directly — it controls how loud a much faster rhythm is, and that faster rhythm is the coupled gamma frequency.

It only appears on phase-amplitude coupled sessions, because it is the only mode that has one.

How much of a second tone, one octave above the carrier, is blended in. At zero the carrier is a pure sine — smooth, but on a long session it can feel thin. Adding a harmonic makes the tone brighter and gives it more presence without changing the rhythm at all.

It is not offered on monaural sessions: monaural sums its two tones before they reach you, so an added harmonic has nowhere to sit.

The wash of sound underneath the tone — the part that sounds like rain, or wind, or distant surf. It is there for two reasons: a bare tone for 40 minutes is unpleasant and fatiguing, and the noise masks small sounds in your room that would otherwise pull your attention.

The color of the noise says which frequencies it emphasises. See what the noise colors mean.

Each session offers its field in two or three versions — the one it was designed around, a heavier one with the top end rolled off so the bed sits further back, and usually an airier one. The player crossfades between them, and the bed is generated separately for each ear, so it surrounds you rather than sitting in a point between them.

A very slow drift of the sound around your head, measured in hertz like everything else — but these numbers are tiny. The catalog runs from 0.005 Hz to 0.08 Hz, meaning one full circuit takes between about twelve seconds and just over three minutes.

It is deliberately slow enough to read as space rather than as movement. Faster than roughly one circuit every twelve seconds it stops sounding like a room and starts sounding like a tremolo, which is why nothing in the catalog goes above that. The purpose is to keep an unchanging sound from turning into a fixed object in one spot, which is what makes long static drones start to feel oppressive. On speakers the effect is much weaker, since the room does its own spatial work.

The orbit is scheduled on the audio clock rather than on the screen refresh, so it keeps circling with your phone face-down and the display off.

Catalog identifiers. The letter or number is the collection the session belongs to — A is Deep Sleep & Overnight Reset, B is Executive Focus & Deep Work, and so on — and the digits are its position within that collection.

They exist so a session can be referred to unambiguously, since several have similar names. Nothing about the code affects how a session sounds.

The method used to create the pulse. A rhythm of 10 Hz can be produced by switching a tone on and off, by summing two tones that drift against each other, or by sending a different tone to each ear and letting your auditory system find the difference — and these sound noticeably different from one another even though the underlying rhythm is identical.

Every session ships with the mode it was designed around. The player offers the alternatives that are physically valid for that particular session, so you can pick the one that suits your headphones and your ears.

A single tone switched on and off at the beat rate. The most direct method and the most audible — you hear a distinct pulsing rather than a subtle one.

It is the native mode for 610 of the 777 sessions. Because the rhythm is in the sound itself, isochronic works on speakers and on a single earbud, and it does not depend on your hearing being equally good in both ears.

Two tones a few hertz apart, one in each ear — say 200 Hz on the left and 210 Hz on the right. Neither ear receives a pulse. The 10 Hz beat is constructed inside your head, at the first point in the auditory pathway where signals from both ears are compared.

This is why headphones are not a recommendation but a requirement: on a speaker the two tones combine in the air before reaching you, and what you hear is an ordinary acoustic beat rather than the binaural one. It is available on 688 of 777 sessions — the exceptions are sessions whose beat is too fast for your auditory system to resolve the timing difference, or whose carrier sits outside the range where that timing cue works at all. Below about 120 Hz the beat stops being a located image and becomes a slow wobble; above about 1 kHz the timing difference stops resolving.

Two tones summed together before they reach you, so the beat already exists in the air as a rise and fall in volume. Like binaural it uses two tones; like isochronic it works on speakers.

Against isochronic, the difference is character: isochronic switches a tone on and off, which is percussive, while monaural produces a continuous swell with no hard edges. It is the smoothest of the speaker-compatible modes, and it is offered on 754 of 777 sessions. The rest are withheld because their beat is large relative to their carrier, and past 12% of the carrier the two tones stop fusing into a beat and start being heard as two separate notes.

Each ear gets its own carrier and its own beat, related by the golden ratio rather than locked together. Because the two sides never quite line up, the combined pattern keeps shifting instead of settling into something predictable.

It needs headphones — on a speaker the two channels sum and the entire distinction disappears.

It is offered on 564 of 777 sessions. Because the right ear runs faster than the left by that golden ratio, a session already targeting 40 Hz would send about 65 Hz to one side — past the range the rest of the catalog stays inside — so the fastest sessions do not offer it.

PAC stands for phase-amplitude coupling: a fast rhythm nested inside a slow one, so the loudness of the quick pulse rises and falls with the phase of the slower cycle. The result is a pulse-within-a-pulse rather than a single flat rhythm.

The name comes from a pattern seen in recorded brain activity, where the strength of a fast rhythm tracks the phase of a slower one. 52 sessions use it natively — the original phase-amplitude collections, plus a study domain that walks the coupling rate across the gamma band from 30 Hz to 80 Hz rather than parking it at 40.

Start with whatever the session ships with — that is the mode it was designed around, and every session page names it.

From there: on speakers, stay with isochronic or monaural. On headphones, binaural is the subtlest and the least intrusive if the pulsing bothers you, and poly-rhythmic is the most textured. If a session feels too percussive, monaural is the smoothest thing you can switch to that still works without headphones.

Because a mode is only offered where it can physically work. Binaural depends on your auditory system resolving a timing difference between your ears, which stops happening above roughly 1 kHz and degrades badly once the beat itself gets very fast. Monaural fails differently: if the beat is more than about 12% of the carrier, the two tones separate and you hear a chord instead of a pulse.

Rather than let you pick something that would quietly not work, the player hides it. A missing mode is not an omission — it means that combination would not have produced the effect its name promises.

A separate control from delivery mode. It governs the carrier — the pitch — not the rhythm.

Fixed holds a single steady tone at the session's stated frequency. Drift replaces it with a Shepard-Risset glissando: a stack of tones an octave apart, sliding continuously downward while the top of the stack fades in and the bottom fades out. The result is a pitch that seems to fall forever without ever actually getting lower — an auditory illusion, used here because a tone that never resolves gives you nothing to anchor on or listen for.

Drift is unavailable on binaural, monaural and poly-rhythmic, all of which encode the beat in an exact relationship between two carriers that a moving stack of octaves would destroy.

A named range of frequencies. Researchers recording electrical activity from the scalp long ago divided what they saw into bands and gave them Greek letters, and those names have stuck for about a century.

On a session page, the band beside a beat frequency simply tells you which range that pulse falls into — it is a label for a number, in the way that "bass" is a label for low notes. Two important cautions are covered in what the band names do and do not tell you.

Infra-Low (up to 0.5 Hz) — slower than one pulse every two seconds. Delta (0.5–4 Hz) — associated with deep, dreamless sleep. Theta (4–8 Hz) — drowsiness, the edge of sleep, deep meditation. Alpha (8–12 Hz) — relaxed wakefulness, eyes closed, calm but alert.

SMR (12–15 Hz) — the sensorimotor rhythm, associated with being physically still and mentally alert. Beta (15–20 Hz) — ordinary active thinking. High-Beta (20–38 Hz) — intense engagement, and at the upper end, agitation. Gamma (above 38 Hz) — the fastest band, associated with high-level binding of perception.

These associations come from what tends to be observed alongside each rhythm. They are correlations, not a control panel — see the caution below.

No, and this is the most important thing on this page. A band label describes the frequency of the audio, not a state the audio will reliably produce. The honest claim is narrow: periodic sound can evoke a measurable, phase-locked response in the auditory pathway. The much larger claim — that this reliably produces a specific mental state — is not well supported.

The second caution is that the association runs the wrong way round to be used as a lever. Deep sleep produces delta activity; playing a 2 Hz pulse does not therefore produce deep sleep, any more than playing a recording of laughter makes something funny. Treat band names as a vocabulary for describing the audio, and judge sessions by whether you like listening to them.

Because the beat moves. A session that begins at 10 Hz and ends at 2 Hz starts in Alpha and finishes in Delta, crossing Theta on the way, so the label changes as it travels. The player shows the band the beat is currently in, and the frequency journey chart shows the whole path in advance.

A few sessions do not travel in a straight line and peak in the middle rather than at either end — one runs 10 Hz up to 40 Hz and back down to 1.5 Hz. The chart shows those waypoints too.

Because 40 Hz has attracted a specific and unusually active line of laboratory research, distinct from the general literature on rhythmic audio. Two collections are built around it and say so in their titles.

That work is genuinely interesting and genuinely preliminary — much of it is in animal models, and the human results are early and not settled. We build the 40 Hz sessions carefully and describe them precisely. We do not claim they prevent, treat or slow anything, and you should be wary of anyone who does.

We would not. Gamma is the fastest band we offer and the sessions built on it are intended for alert, effortful work. Using a stimulus aimed at active processing at the moment you are trying to disengage is working against yourself.

For sleep, use the Delta and Infra-Low sessions, which descend rather than hold, or the Theta sessions if you want the drifting edge rather than full sleep. There is a further wrinkle worth knowing: audio playing while you are still awake can delay sleep onset even when the same audio helps once you are under, which is why the sleep timer matters. The 40 Hz protocol guide and using sound to fall asleep both go into this.

The measurable part is quick. A tone modulated at 40 Hz produces an auditory steady-state response that appears within seconds and settles into a stable pattern over the first minutes of listening. That much is well characterised and has been since 1981.

What we will not give you is a precise number for when you should *feel* something. You will see confident figures quoted — eight minutes for binaural, three for isochronic — and they are not supported by anything we can find. In practice, treat the first five minutes as setup rather than work, and judge a session by whether the block went well rather than by watching for an onset.

Yes, provided you use isochronic delivery — which is what these sessions ship as. The pulse is a real change in loudness, so a speaker reproduces it exactly.

Binaural is the mode that cannot survive a speaker, and at 40 Hz it is the wrong choice anyway: binaural beating depends on the two tones being close together, and a 40 Hz difference sits at the edge of where the effect forms at all. For gamma specifically, isochronic is both the more practical and the better-supported option. See the 40 Hz protocol.

Check whether mono audio is switched on. Both iOS and Android have an accessibility setting that combines the left and right channels into one identical signal sent to both ears. It is easy to enable and forget.

That setting removes binaural beats entirely — with both ears receiving the same summed signal there is no difference left to compare, exactly as if you were listening on a speaker. Isochronic, monaural and phase-amplitude sessions are unaffected. See headphones or speakers.

They describe how the energy in the noise is spread across the frequency range — the same way "color" describes how energy is spread across the spectrum of light, which is exactly where the naming convention comes from.

White has equal energy at every frequency. Because of how hearing works it sounds bright and hissy, like an untuned radio. Pink falls off steadily as frequency rises, sounding balanced and natural — steady rain, or wind in trees. It is the most common field in the catalog. Brownian falls off more steeply still, leaving a deep, soft rumble like distant surf. Violet does the opposite of brownian and rises with frequency, which is thin and airy; it appears rarely, and only where a session needs a field that stays out of the way of a low carrier.

Modifiers on the base color, describing how the field has been shaped. Deep, Sub and Dark push the energy lower, making the field heavier and more distant. Light and Soft do the reverse or simply reduce its level, keeping it further back behind the tone.

Filtered and Narrowband restrict the field to a limited range rather than letting it run across the whole spectrum, which makes it more like a specific texture and less like general noise. Sub-Bass pushes the energy below where most of hearing lives, so it is felt as weight more than heard as sound. Masking marks a field whose level was chosen to cover room noise rather than to sit politely behind the tone — it is the loudest, most present kind in the catalog. Combinations such as "Deep Sub Brownian" stack these — that one is about as low and soft as the catalog goes.

Not currently. The noise field is part of the session specification rather than a layer on top of it — level, color and shaping were chosen against the specific carrier and pulse of each session, and removing it would leave a bare tone that most people find fatiguing within a few minutes.

If you want less of it, the sessions with "Soft" or "Light" fields carry the least, and the session page states the field for every session before you play it.

$3 a month, or $30 a year — the annual option works out about 17% cheaper. Unlimited access to the complete Brainwavest Core library and future Core sessions. There are no per-session purchases, advertisements, or hidden Core tiers. Future guided or educational product lines will always be identified separately before purchase.

New members start with 3 free days. The yearly plan is preselected because it is the cheaper of the two per month; the monthly option sits beside it on the same screen and is one tap away.

You get the complete library for 3 days without being charged. Starting the trial does need a card — it is authorised so the membership can continue without interruption, not charged — and it is one trial per account.

Unless you cancel first, the trial turns into the plan you chose when it ends: $30 a year by default, or $3 a month if you picked monthly. It then renews automatically until you cancel. The exact charge date is on the screen where you enter the card, in the confirmation, and on your account page for the whole 3 days.

Cancel at any point before that date and you are charged nothing at all — you keep access for the rest of the free days and the membership simply ends. If no usable card is on file when the trial ends, nothing is billed and the membership ends rather than going into arrears.

Separately, and before any of this, three complete sessions are free with no card at all.

Three complete sessions — not previews or excerpts, but any three sessions in the library played start to finish. You can also browse the entire catalog and read every session's full specification without an account at all.

Your first session starts without an account. After you have genuinely listened for a minute, one passwordless email sign-in unlocks the remaining two on that device. No card is required, and you are told exactly where you stand before the next session starts.

The free counter is stored in your browser on that one device. Clearing your browser data resets it, and a different device or a private window starts with its own count.

That is a deliberate choice rather than a bug. Defending three free sessions properly would mean fingerprinting people, and a paywall that invasive is worse than one that leaks a little. The real boundary is the account, not the counter.

You did not, because there are none. Enter your email and we send you a link; clicking it signs you in. That is the whole system.

It means there is no password to forget, to reuse from another site, or for us to store badly. If the link does not arrive, check your spam folder and confirm the address — and note that the link is single-use and expires, so request a fresh one rather than reusing an old email.

As many as you like. Sign in on each one and your membership, favorites and listening history follow you.

From your account page, in one tap. No email, no retention flow, no phone call.

Cancelling takes effect at the end of the period you have already paid for — you keep full access until then, and are not billed again.

Cancelling during the 3 free days works the same way and costs nothing: you keep access to the end of the trial and no charge is ever taken.

Billing questions and refund requests go to support@brainwavest.com. The current policy is on the refunds page.

Brainwavest is an installable browser app. On a supported phone, tablet, or desktop, use your browser’s install or “Add to Home Screen” action. It then opens in its own app window while keeping the web version current.

There are no audio files to download: each session is a specification and the audio is synthesized on your device. After one connected visit, the installable app caches the Core signal catalog, synthesis engine, Brainwavest Today, Signature Collection, and recently visited pages for offline use.

Account sync, membership changes, checkout, and any page not yet cached still need a connection. For the most dependable offline access, install Brainwavest and open Today once while connected. See the exact offline boundary on the offline page.

Signed out: your theme, volume, filters, favorites, Today choices, session-fit answers, first-visit date, free-session count, and offline files live in your browser. The site also sends anonymous daily counter increments for a small, disclosed set of acquisition, activation, return, completion, and fit events. Those counters contain no person, account, device, IP address, or individual event timeline.

Signed in: your email, membership status, favorites and listening history can follow you between devices. A recent active membership check may be cached locally for up to seven days so paid access survives a connection outage. Audio is generated on your device and is never recorded or uploaded, and we have no microphone access. See the privacy policy.

Because it is generated fresh rather than replayed. The noise field is genuinely random each time, and the pulse carries a small amount of deliberate irregularity instead of being metronomically exact.

The irregularity is intentional: a perfectly rigid rhythm is something your attention locks onto and then starts predicting, which is the opposite of what these sessions are for. The specified numbers — carrier, beat, ramp, depth — are held exactly. What varies is the texture around them.

Yes for the audio itself — there is nothing to sync to, so Bluetooth latency is irrelevant here.

One caution matters for binaural and poly-rhythmic sessions: turn off any spatial audio, 3D audio, head-tracking, or upmixing feature your headphones or phone offer. Those work by re-mixing the left and right channels, which is precisely the relationship those two modes depend on. Isochronic and monaural are unaffected.

Any current version of Chrome, Edge, Firefox or Safari, on desktop or mobile. The engine uses the browser's standard audio system, with a fallback path for older browsers that lack the modern interface.

If a session will not start, the usual causes are a browser tab that has been muted or a device on silent — and on iPhone, the physical silent switch mutes web audio.

It depends entirely on what "work" means, and we would rather split that than blur it.

That periodic sound evokes a measurable, phase-locked response in the auditory pathway is reasonably well established — this is the frequency-following response, and it is observable in a laboratory. That this reliably produces a specific cognitive, emotional or clinical outcome is much weaker, and study quality in this field varies widely: small samples, inconsistent controls, and a strong publication bias toward positive findings.

So: we build the audio carefully, publish exactly what it does, and let you judge whether you like listening to it. What we will not do is convert a modest laboratory finding into a promise about your sleep or your focus. More on the science page.

The names describe the design intent behind the audio — the band it targets and the character of the field — and some of them borrow anatomical or physiological vocabulary because that is the vocabulary the underlying research uses.

They are not claims about what will happen in your body. A session called "Amygdala Calmer" is a session designed with that intent, not a session that has been shown to do it, and none should be understood as a treatment for any condition. If a name reads like a promise, read it as a description instead.

No, and no. Brainwavest is a wellness and relaxation tool. It does not diagnose, treat, cure or prevent any condition, and it is not a substitute for medical or psychological care.

If you are managing a health condition, treat this as you would any other relaxation practice — something that may sit alongside your care, discussed with your clinician, and never something to stop or delay treatment for.

Email hello@brainwavest.com and a person will read it. For billing specifically, support@brainwavest.com reaches the same people with the right context attached.