A working index of the 132 frequencies we've mapped to measurable nervous-system states. Grouped by the seven classical bands. Each one cited. Each one playable, in real binaural, from the browser. Headphones required.
Click any frequency row to play real binaural audio in the browser. Headphones required. You'll hear the effect within 60 seconds.
Look up a specific Hz before your session. Use the search bar or browse by band. Every entry shows the use case, mechanism, and citation.
Scroll to the Protocol Builder at the bottom. Bookmark up to 3 frequencies and save them as a named stack for use in the app.
New to brainwave bands? Use the left sidebar to jump to Delta (0.5-4Hz), Theta, Alpha, Beta, Gamma, or Solfeggio. Each band opens with a full explanation.
Every frequency links its primary study. If a claim has no RCT behind it, it's labeled as traditional use. You will not find unsourced absolutes here.
Pick a goal. We'll surface the best frequency to start with, explain the mechanism, and link you to a live session in the browser.
Add up to 3 frequencies from the index above to build a custom session protocol. Drag into order, adjust duration, then copy the stack to use in the app.
The library is not a compilation of claims. It is a filtered subset of the published frequency research that met specific inclusion criteria. Here is what those criteria were.
Animal models and in-vitro findings are excluded from the library unless corroborated by at least one human trial. 40Hz gamma is the exception: Iaccarino 2016 is a mouse model, but subsequent human Phase III trials at MIT validate its inclusion. Every other frequency has a human study behind it.
If the proposed benefit cannot in principle be tested or measured, the frequency is not included. "Spiritual elevation at 528Hz" is not included. "528Hz solfeggio associated with decreased anxiety per subjective scales" is a claim that can be evaluated, even if the evidence is weak. The evidence tier label reflects that evaluation.
The library does not include frequencies on the basis of being "natural" or "cosmic" without physiological evidence. The Schumann resonance at 7.83Hz is included because it falls at the theta/alpha boundary with documented human brainwave overlap, not because it is "the Earth's frequency." The physics justification is not mystical. It is mechanistic.
The frequency must produce the documented effect when delivered as binaural beat audio through standard stereo headphones, not lab-grade EEG stimulation equipment or clinical hardware. If a study's protocol required equipment unavailable to a consumer, the frequency is listed with that limitation noted.
Frequencies with documented adverse effects in unsupervised populations are excluded. Some research explores frequencies in ranges associated with seizure activity. Those are not in the library. We are building a consumer wellness product, not a clinical stimulation device.
800+ studies were screened. 132 frequencies met all five inclusion criteria with at least one citation. Many more frequencies appear in the broader literature but were excluded for failing one or more of the criteria above.
Most explanations of binaural beats are either too simplified to be accurate or too technical to be useful. Here is a version calibrated for someone who wants to actually understand what is happening in their auditory cortex.
Your left ear receives a 200Hz pure tone. Your right ear receives a 240Hz pure tone. Critically, these two tones never mix in the air. Binaural beats require stereo headphones because the mixing happens inside your brain, not outside it. This is why mono speakers do not produce the effect.
Your superior olivary complex (the brain region that processes interaural timing differences) perceives the difference between the two tones: 240 minus 200 equals 40Hz. Your brain generates a phantom perception of a 40Hz oscillation. This third frequency is not in the audio. It is created entirely inside your auditory cortex.
The brain's neural oscillations, which operate at a range of frequencies across different regions, begin synchronizing to the 40Hz beat your auditory cortex is generating. This is the frequency-following response: neural circuits that can oscillate at 40Hz start doing so more coherently. EEG shows measurable gamma power increase within 7-15 minutes of sustained listening.
The carrier frequencies (200Hz and 240Hz in the example above) must be below 1,000Hz for the effect to work. The brain's interaural processing only handles low frequencies. You cannot produce a reliable 100Hz gamma beat this way; the mechanism breaks down. Mortis uses carrier frequencies in the 100-300Hz range for all protocols. Frequencies above this range use isochronic tones instead, which work through a different (monaural) mechanism.
The foundational reference: Lane et al. (1998), "Binaural Auditory Beats Affect Vigilance Performance and Mood," Physiology and Behavior. Double-blind crossover RCT. This is the study that established the frequency-following response in healthy subjects using a controlled task-performance paradigm. PubMed ID: 9682782.
The space around binaural entrainment has accumulated several adjacent concepts that are often lumped together in wellness marketing. Most of them are real phenomena. Most of them are not the same thing. Here is the specific distinction for six of the most common ones.
Rapid on-off pulses of a single tone at a specific rate. Unlike binaural beats, isochronics can work through speakers (no headphones required). The entrainment mechanism is different: it relies on the auditory cortex responding to the pulse rate directly rather than to an interaural difference. Generally weaker evidence base but useful for users who cannot wear headphones.
Mortis uses: isochronic for gamma range only (40Hz+). Binaural for all other bands.
Two slightly different frequencies mixed into a single audio channel before delivery. The "beat" is produced in the air, not in the brain. This bypasses the superior olivary complex and does not produce a true entrainment response in most listeners. Some research suggests monaural beats can still produce mild state effects, but the evidence is weaker than for binaural.
Mortis does not use monaural beats. The mechanism is too weak to justify at evidence-tier 1 or 2.
A set of six specific tones (396, 417, 528, 639, 741, 852 Hz) derived from medieval Gregorian chant notation. Marketed with strong claims about cellular repair, DNA activation, and emotional healing. None of these claims have peer-reviewed evidence. Solfeggio tones are played as fundamental frequencies, not as binaural carrier differences. They produce a listening experience, not an entrainment response.
Mortis includes solfeggio at Tier 3 to 4 with explicit "observational only" labels.
The argument that music tuned to A=432 Hz is more "natural" or "healing" than the standard A=440 Hz tuning. Some listening preference studies show people report 432 Hz as more relaxing in double-blind comparisons. There is no peer-reviewed evidence of physiological effect beyond self-reported preference. It is a music production variable, not a frequency entrainment mechanism.
Unrelated to binaural beat protocol selection. Mortis allows 432 Hz as an ambient layer preference only.
Binaural microphones record spatial audio by capturing sound exactly as a human head would hear it. The result is a 3D listening experience through headphones. This is a spatial audio technology, unrelated to binaural beat entrainment. The word "binaural" means "two ears" and is used in both fields, which causes the confusion. A binaural ASMR recording will not entrain brainwaves.
Two different products that share a word.
Immersive live sound sessions using bowls, gongs, and resonating instruments. Rich overtone spectrum, powerful subjective experience, but not a controlled frequency entrainment protocol. The tonal content is complex and variable across instruments and sessions. Effects reported by practitioners are real but mostly uncharacterized in peer-reviewed research.
Different tradition, different evidence base. Mortis is not a sound bath replacement and does not claim to be.
The point of this table is not to discredit any of the adjacent concepts above. Most of them are real phenomena with their own literature and their own use cases. The point is that they are not binaural beat entrainment and should not be used interchangeably with it. Mortis is specific about what it ships: binaural beats in the 1 to 40 Hz carrier difference range, with isochronic in the gamma range, everything else clearly labeled at Tier 3 or 4.
Deep sleep, HGH secretion, glymphatic waste clearance. Nedergaard 2013 showed delta-stage sleep drives lymphatic outflow from the brain.
View delta →Hypnagogic creativity, divergent thinking, emotional integration. The bandwidth of deep contemplative states in long-term meditators.
View theta →Parasympathetic activation, HRV elevation, calm alertness. The idle baseline of a healthy resting nervous system. Most associated with measurable HRV improvement.
View alpha →Active cognition, sustained attention, verbal processing. 18Hz is the primary focus carrier. High beta (25-30Hz) can amplify anxiety if used without a grounding base.
View beta →Neural binding, cross-region synchrony, peak performance state. 40Hz is the primary carrier, the only frequency with Phase III clinical trial data (Iaccarino 2016).
View gamma →432Hz, 528Hz, and the 9-tone solfeggio scale. Observational and traditional evidence. Mechanistically distinct from brainwave band entrainment. Labeled as such.
View solfeggio →First-session expectations are the most common source of protocol errors. Here is what the research predicts and what you are likely to experience at each stage.
Your auditory cortex is detecting the two tones and beginning to register the beat frequency. Nothing else has happened yet. If you notice the sound feeling "weird" or pulsing, that is the binaural beat itself. This is correct.
What to do: nothing. Keep headphones on. Do not adjust volume.
If your protocol includes a breathwork layer, run it here. The structured breathing is not the session - it is an autonomic onset accelerant. Coherent breathing at 5.5 breaths per minute reduces cortisol quickly and primes parasympathetic response before the frequency takes hold.
If you skip this: the frequency still works. Onset is slower by 3 to 5 minutes.
This is where entrainment is actually occurring. The beat frequency is being relayed from auditory cortex through thalamic loops. Most people feel nothing dramatic here. A mild relaxation or sense of quiet is common. Gamma sessions may produce a subtle alertness. Do not expect a "hit." This is a physiological process, not a psychoactive event.
Common mistake: stopping because "nothing is happening."
By 12 minutes, EEG power in the target band measurably shifts across cortical regions in most subjects. This is when the session does the most work. Alpha sessions: a deepening calm. Delta: heaviness or early sleep pressure. Gamma: clarity, reduced cognitive noise. These are subtle on session one, stronger by session ten.
Where to end: 12 minutes minimum. 20 to 25 minutes for best HRV outcomes.
Stay still for 2 minutes after the session ends. The post-session HRV read is most accurate when taken during this window, before movement raises heart rate. This is the single data point the Mortis matrix is built from. Do not skip it.
The app reads HRV automatically if Apple Watch access is enabled.
Timeline based on published binaural beat and EEG entrainment research. Herrmann, 2001; Lane et al., 1998; Thut et al., 2011. Individual onset timing varies by baseline autonomic state and session history.
The voice intake handles this automatically after you begin. But if you want to choose your first session manually, here is where to enter based on what you are actually trying to do right now.
Delta band entrainment in the 1-3Hz range primes the nervous system for slow-wave sleep transition. The Nedergaard 2013 glymphatic study showed delta-stage sleep drives cerebral spinal fluid exchange. Use 2Hz, not deeper delta, for the sleep onset application. Pair with 4-7-8 breathing for the first 6 minutes.
40Hz is the most-used frequency in the beta cohort and the most evidence-supported (Iaccarino 2016, Nature). Gamma band entrainment increases cross-cortical synchrony, accelerates neural binding, and produces the clearest subjective shift of any band in acute-session user reports. Morning application (within 60 minutes of waking) pairs with the natural cortisol rise for maximum priming effect.
Alpha (8-12Hz) is the band most directly associated with parasympathetic activation and RMSSD improvement. Brook et al. 2013 showed HRV improvement with slow breathing interventions that produce alpha-range baroreflex engagement. The 10Hz carrier is the strongest acute-effect frequency in the alpha band. When your morning HRV is below baseline, this is the prescription.
These are default starting points for new users. After 5 sessions, the voice intake and personal matrix will produce protocol recommendations that are personalized to your actual response data rather than goal-based defaults.
The most common first-session experience is: "I listened, I waited for something to happen, and mostly I just lay there." This is not a failure of the protocol. Here is exactly what is happening, and what to do next.
Session one is calibration. The brain is not habituated to tracking a binaural beat. The auditory cortex needs 3-5 sessions before the frequency-following response fires predictably. Your RMSSD data from session one is still meaningful even when the subjective experience is flat. Check your post-session HRV in the app, not your subjective impression.
What to do: run the same protocol for sessions 2 and 3 before evaluating. Do not switch frequencies yet.
This is the most common session-one experience that correlates with positive HRV response. The frequency entrainment is working; the subjective effect is subtle because the change is autonomic, not cognitive. You are not supposed to feel a clear altered state. You are supposed to come out with a higher post-session RMSSD.
What to do: compare your pre-session and post-session RMSSD in the app. That number is what you are tracking, not the subjective experience.
The tone will always be audible in the first session. After 3-5 sessions, the auditory cortex habituates and the beat recedes into the background. Users who report strong distraction in session one almost universally report the tone becoming "invisible" by session four. The habituation is required for the entrainment to work efficiently.
What to do: lower the volume slightly (60-65dB target) and run a breathwork pattern for the first 4 minutes before letting it go passive. The breathwork gives the conscious mind something to do while entrainment begins.
A lower post-session RMSSD in session one is unusual but not alarming. The most common causes: the Apple Watch reading was taken too quickly after ending the session (wait 2 minutes), you selected a high-beta frequency that is activating rather than calming, or your pre-session baseline was taken mid-activity. Re-check your measurement protocol before changing the frequency.
What to do: verify your measurement timing (2 min post-session rest before reading). If the pattern continues after session 3, switch from gamma or beta to alpha or delta.
Do not evaluate this product until session five. Not because we are asking for charity, but because the frequency-following response genuinely requires 3-5 sessions to stabilize. The personal matrix needs a minimum of five RMSSD data points before its recommendations are worth acting on. Judgment before session five is judgment on calibration data, not on the actual protocol.
Not every moment is a session opportunity. Running a session in the wrong physiological state does not neutralize; it produces noisy data and wastes the calibration window. The six situations below are when Mortis explicitly recommends skipping the session and doing something else. Knowing when not to run is a feature, not a bug.
A session run on severe sleep debt does two things: produces a pre-session HRV reading that contaminates your baseline, and fails to produce a meaningful delta because the nervous system has no parasympathetic headroom to move into. The right response to sleep debt is a 20-minute nap, not a 20-minute session.
What to do instead: nap, hydrate, log nothing.
An immune response elevates resting heart rate and suppresses HRV for reasons completely unrelated to your nervous system state. Running a session during acute illness produces a reading that the matrix will try to interpret as stress, which is incorrect and corrupts your 7-day baseline. Sleep and hydrate until the illness passes.
What to do instead: rest. Re-baseline 3 days after symptoms clear.
Post-exercise HRV is suppressed for reasons of training physiology, not chronic stress. A session in this window will show a large positive delta because the HRV is rebounding naturally, not because the frequency moved anything. This inflates your personal effect size with a false signal. Wait until HR has returned to within 10 beats of resting.
What to do instead: hydrate, cool down, wait 90 minutes, then run if still useful.
Stimulants produce a sympathetic spike that lasts 60 to 120 minutes. Running a session in this window produces a reading where the frequency's effect is mixed with stimulant washout. Whichever direction the HRV moves, you cannot attribute it cleanly. Either run the session before the stimulant or wait until the effect clears.
What to do instead: run sessions pre-caffeine whenever possible. That is the cleanest condition.
The product is a measurement loop, not a therapeutic intervention. During acute grief or an emotional crisis, the right response is human contact, a therapist, or medical care, not a binaural session. The frequency may or may not help; what it will definitely do is produce a confused data point in your matrix that is not about the frequency at all.
What to do instead: call someone. Mortis will be here when the acute phase passes.
If the only reason you are opening the app is to maintain a streak number, skip. The product was explicitly designed to not reward streak compliance. A session run out of guilt or habit inertia produces poor data and trains the wrong relationship with the tool. A missed day is a data point about your life, not a failure of discipline.
What to do instead: skip the session, note the reason, run tomorrow if the conditions improve.
The reason this list exists is simple: the measurement loop is only as good as the conditions under which the measurements are taken. A product that encourages you to run sessions regardless of state produces a personal matrix that is noisy and hard to interpret. A product that tells you when to skip produces a matrix where every session counts. This is one of the design choices we expect to be copied eventually. For now, it is the distinguishing behavior.
Frequency sensitivity is not fixed. The response you have in session one is not the response you will have in session thirty. Here is what the research says about tolerance, adaptation, and why this matters for long-term protocol design.
The first five sessions establish your HRV baseline and give the recommendation engine its first calibration data. Many users report feeling nothing on session one. This is not a tolerance issue; it is a baseline-building issue. The app is learning your resting RMSSD before it has enough data to measure a delta against it.
Most users report the clearest subjective response in this window. The recommendation engine has enough calibration data to consistently match frequency to state. HRV deltas are typically highest here. This is when frequency entrainment is most reliably measurable at the individual level. Beta cohort median RMSSD delta: +11ms in this range.
By session 21 most users have identified their highest-response frequency and settled into a protocol. Subjective novelty decreases, but HRV consistency increases. The goal shifts from discovery to optimization: dialing in duration, breathwork pairing, and time of day to maximize the reliable delta rather than chasing new sensations.
Some users rotate frequencies to preserve sensitivity. Changing bands every 4-6 weeks is a reasonable approach, supported by entrainment research on habituation. The personal matrix tracks your per-band session count, so you can see if you are over-indexing on a single frequency.
The research on binaural beat tolerance is sparse. Most studies are short-term (2-8 weeks). We do not make claims about what happens at session 200. The data we have from beta users at 90+ sessions shows continued HRV response with no significant degradation, but this is observational Tier 3 evidence, not an RCT.
You have read the bands. The voice intake does this in 30 seconds. But if you want to think through it manually before your first session, this is the logic.
The voice intake picks a starting band. Your actual best band often emerges over the first two weeks as the pre-post HRV data accumulates. Here are four composite examples drawn from the beta cohort, showing how the starting band was chosen, what changed by day 14, and which band produced the largest personal effect size. Names are pseudonyms; the session patterns are real.
"I cannot turn my brain off at night. I wake up tired even after eight hours." Intake recommended 3Hz delta for sleep onset.
Delta produced a flat HRV delta. Not negative, but not positive. Matrix suggested switching to 10Hz alpha in the morning instead of delta at night.
10Hz alpha, morning. Her sleep was not the root problem. Her sympathetic load through the day was. The morning alpha session produced a +8ms RMSSD delta and, indirectly, better sleep.
"I want to hit my race HRV numbers on race day." Intake recommended 40Hz gamma pre-training and 2Hz delta overnight.
Gamma produced modest deltas. Delta overnight produced large overnight RMSSD improvements. The breakthrough came when he added 7.83Hz Schumann on recovery days.
7.83Hz Schumann, post-workout. His nervous system needed parasympathetic recovery far more than pre-activation. Gamma was wasted on him; Schumann was underused.
"I need focus for long writing sessions. Anxiety sometimes derails me mid-afternoon." Intake recommended 10Hz alpha for stability.
Alpha was helpful but not dramatic. The app suggested trying 40Hz gamma 30 minutes before the writing block. The HRV delta tripled.
40Hz gamma, pre-writing. The anxiety was a downstream symptom of an under-activated focus state. Gamma produced neural binding; the anxiety disappeared without being directly targeted.
"I have been meditating for fifteen years. I want something that measures. I do not need guidance." Intake recommended 6Hz theta for experienced practitioners.
Theta worked well. But stacking 6Hz theta with 5.5 breath-per-minute coherent breathing, rather than with no breathwork at all, produced the cleanest effect.
6Hz theta + coherent breathing. For an experienced meditator, the breath pairing was the variable that made the difference, not the band.
The pattern across the four cases: the voice intake picks a reasonable starting band from stated context. The data tells you whether the starting band was right. The matrix then suggests adjacent bands to try if the delta is flat. Three of the four cases ended up on a different primary band than the one Claude first suggested. This is expected. The intake is a starting point, not the answer.