How to Use CRUX

Simple guidelines to help you get the most from your binaural audio sessions.

🧭 Where would you like to start?

  • I want to feel calmer right now → Box Breathing or Heart–Brain Coherence (Balanced preset) for a few minutes is a good place to begin.
  • I want a quieter mind → Try the Calm or Meditation beat, layered softly with Pink or Brown Noise.
  • I want deeper, more restful sleep → Try the Wind Down routine below — Sleep beat, Brown Noise, and the Body Scan together.
  • I want to think more clearly → For sustained attention, the Focus beat with White Noise works well. For complex problem solving or higher-order thinking, try the Reasoning beat (64 Hz Gamma).
  • I want some quiet from the noise around me → Noise Therapy is a good starting point — try Brown Noise, Heavy Rain, or the Pure Tone if you want to find your own pitch.
  • I want to ease into stillness → The Body Scan is a gentle place to start — just lie down, press play, and let the narrator guide you.

🌙 Wind Down — A pre-sleep routine

A simple sequence that uses all three tools together. Most people are settled well before it ends.

  1. Open Noise Therapy and select Brown Noise or Heavy Rain. Set the volume low — around 30%.
  2. In the Binaural Beats player, select Sleep (1 Hz Delta). Set it just above the noise so you can feel it beneath.
  3. When you're comfortable, open the Body Scan and press play. Let the narrator guide you the rest of the way.
If you wake during the night, skip straight to Brown Noise or the Body Scan — no need to start from the beginning.

🎧 Before You Begin

  • Use stereo headphones. Binaural beats only work when each ear receives a slightly different frequency. Speakers blend the two channels and eliminate the effect entirely.
  • Lower your volume first. Set your device to a low, comfortable level before pressing play. Loud audio causes discomfort and reduces the benefit. The audio fades in gently over the first three seconds — there is no need to start loud.
  • Find a quiet space. A calm environment helps your mind settle faster. If background noise is unavoidable, use the Noise Therapy section to mask it.

🧠 Choosing a Binaural Beat

Binaural beats work by playing two slightly different tones — one in each ear. Your brain perceives the small difference between them as a single pulsing "beat." Because the effect is created inside your brain from the two separate signals, stereo headphones are essential — playing the sound through a speaker won't work.

How to use them

  1. Put on stereo headphones (not a single earbud or a speaker).
  2. Pick a track matched to your goal — lower frequency ranges (delta/theta) are commonly used for sleep, deep relaxation, or meditation, while higher ranges (alpha/beta/gamma) suit calm focus, alertness, and higher-order thinking.
  3. Listen for around 10–15 minutes, ideally with your eyes closed or while doing a calm activity.

Which beat to choose

Binaural beats — two tones, one in each ear; the perceived beat gently encourages a matching mental state. Slower beats (delta/theta) suit rest and relaxation, while faster beats (alpha/beta/gamma) suit calm focus, alertness, and higher-order thinking.

  • Focus (10 Hz Alpha) — Concentration, studying, or any task requiring sharp mental attention.
  • Calm (12 Hz Alpha) — Unwinding after a demanding day or easing into rest.
  • Sleep (1 Hz Delta) — Falling asleep or returning to sleep after waking at night.
  • Creativity (7 Hz Theta) — Open-ended thinking, problem solving, or creative work.
  • Energy (25 Hz Beta) — Physical exercise or building mental alertness before a demanding task.
  • Reasoning (64 Hz Gamma) — Higher-order thinking, complex problem solving, or moments when you want your mind at its clearest.
  • Meditation (6 Hz Theta) — Daily mindfulness practice or grounding after a stressful event.
  • Pain Management (9 Hz Alpha) — Encouraging deep relaxation to help ease physical tension and discomfort.
  • Anxiety (4 Hz Theta) — Reducing stress and quieting an overactive nervous system.

Bilateral tracks (left–right audio) — these work differently from binaural beats: instead of two tones, a single soft tone alternates between your left and right ear at a steady pace (50, 60 or 70 pulses per minute), so stereo headphones are needed. Many people find the predictable side-to-side rhythm grounding — a simple, steady pattern to settle into — with the slower pace feeling calmer and the brisker pace a little more alert.

  • 50 BPM Bilateral — Slow, rhythmic left-right audio — a gentle pace for unwinding or quieting a busy mind.
  • 60 BPM Bilateral — Steady left-right audio at a natural, comfortable rhythm — easy to settle into.
  • 70 BPM Bilateral — Brisker left-right audio for those who find a livelier rhythm easier to relax with.
Tap to open Binaural Beats

The science. The binaural beat phenomenon was first documented by Heinrich Wilhelm Dove in 1839 and described in neurological detail by Gerald Oster in Scientific American (1973): when two tones of slightly different frequencies are delivered separately to each ear, the brain perceives a single pulsing beat at the difference between them. A review by Chaieb et al. (2015), published in Frontiers in Psychiatry, examined controlled research and found consistent evidence that the perceived beat influences cortical activity, alertness, mood, and cognitive performance in ways aligned with the target brainwave frequency range. A subsequent meta-analysis by Garcia-Argibay et al. (2019), covering twenty-two randomised controlled trials, found significant effects on anxiety, pain perception, and mood. Bilateral tracks use a different mechanism — a single tone alternating between ears at a steady rhythm — and draw on a separate literature linking predictable rhythmic auditory stimulation to nervous system regulation and reduced arousal. The Chaieb et al. review is freely available via NIH PubMed Central.

▶️ Playing a Session

  • Swipe or use the arrows in the Audio Library to browse, then tap the centre card to load it into the player.
  • Press the large Play button to begin. Audio fades in softly over the first three seconds.
  • Each session is 15 minutes and fades out gently over the final five minutes — no abrupt ending.
  • The and buttons jump to the previous or next binaural beat.
  • Space bar pauses and resumes; ← → arrow keys change track — useful if you have your phone in your pocket.

🌊 Noise Therapy

White, pink, brown noise, and a heavy rain recording can be played alongside — or instead of — binaural beats. Steady background noise masks sudden environmental sounds that can trigger a stress response, giving your nervous system something predictable to hold on to.

  • White noise — all frequencies at equal strength, like a steady fan or static. It masks sudden sounds that can trigger a stress response, helping your nervous system settle, and is good for concentration and blocking unpredictable noise.
  • Pink noise — louder at low frequencies, softer at high — the pattern of rainfall, wind, and rivers. Promotes deeper sleep stages and reduces the brain's sensitivity to intrusive thoughts.
  • Brown noise — a heavy bass rumble, like distant thunder or ocean swells. The deepest tone of the group, and a popular choice for reducing hypervigilance at night.
  • Heavy Rain — Rain on a tin roof — a dense, enveloping downpour that blends well with any binaural beat and masks even persistent background noise, wrapping the room in steady, grounding sound. Particularly effective for sleep and deep focus.
  • Gentle Rainforest Waterfall — a recording of water tumbling over mossy rocks in a rainforest. Soft, flowing and continuous — soothing for focus, relaxation or drifting off — and it comes with a matching full-screen video.
  • Gentle Ocean Waves — the steady wash of waves rolling onto the shore. A slow, rhythmic coastal sound that calms the mind for unwinding and sleep, also paired with a full-screen video.
  • Pure Tone — a single, clean tone you can tune to your own pitch and keep just below your tinnitus. Played gently, it blends with the ringing so your brain notices it less, easing the distraction and helping you rest or focus.
  • Enable Auto-sync to have noise start and stop automatically with your binaural audio.

Full-screen nature videos

Gentle Rainforest Waterfall and Gentle Ocean Waves each pair their sound with a matching looping video for a more immersive experience.

  • Tap the tile to start the sound and open the video full-screen — it fills the screen on any device.
  • Tap the video (or press Esc) to close it. The sound keeps playing, so you can adjust the volume or stop it from the card.
  • The video is silent and loops smoothly — the sound comes from the audio, and the video only downloads when you first open it.

Using Pure Tone for tinnitus

Pure Tone is a self-help comfort tool, not a treatment — but used gently it can make tinnitus easier to live with.

  • Find your pitch. Move the slider until the tone sits closest to your tinnitus — often a high pitch (roughly 1,000–8,000 Hz). Nudging it slightly either side can improve the blend.
  • Keep it gentle. Set it low and comfortable — just below your tinnitus, never loud or painful. If it ever makes your symptoms worse, stop.
  • Use it the way that suits you. In the moment — short sessions (around 10–60 minutes) when the ringing bothers you most; as a soft backdrop — playing quietly for longer stretches, which some people find reduces their awareness of it over time; blended — layered or alternated with a noise or rain so you're not focused on the tinnitus alone.
  • Listen on good headphones for a steady, accurate tone, and keep the volume modest.
  • Check in weekly. A quick note on loudness, annoyance, sleep, and stress shows what's helping.
  • Pair it with other support. Relaxation, good sleep habits, and professional care (CBT, an audiologist, hearing aids if needed) do the most together.

See a clinician if your tinnitus worsens or your hearing changes — and seek prompt care for sudden, one-sided, or pulsing tinnitus, dizziness, ear pain, or hearing loss.

Tap to open Noise Therapy

The science. Steady background noise reduces sleep onset latency and masks the unpredictable environmental sounds that trigger a stress response in the nervous system. A randomised controlled trial by Messineo et al. (2017), published in Frontiers in Neurology, found that broadband noise — the category that includes white, pink, and brown noise — significantly reduced the time it takes to fall asleep in healthy adults exposed to ambient noise. Separately, a body of research on acoustic masking shows that steady, spectrally rich sounds reduce the brain's sensitivity to intrusive background noise by raising the ambient threshold, making sudden sounds less disruptive. The Messineo et al. trial is freely available via NIH PubMed Central.

💨 Box Breathing

Box breathing is a regulated breathing technique used to ease stress and tension. It activates the parasympathetic nervous system, slowing heart rate and calming the body's threat response. The pattern is simple:

Inhale

4 sec

Hold

4 sec

Exhale

4 sec

Hold

4 sec

Breathe from your belly, not your chest, and stay relaxed during each Hold — there's no need to fill your lungs to their maximum capacity. The first few cycles may feel awkward, so give yourself a few minutes to adjust.

Your mind may wander at first, but after a few minutes the rhythm will feel more natural. Some people feel a little light-headed when they first start, so take a break if you feel uncomfortable. Your mind and body will adapt after two to four weeks of regular practice.

Box breathing works best with regular use — first thing in the morning, just before bed, or whenever you feel anxious.

Works well with the Binaural Beats sessions.

Tap to open Box Breathing

The science. Box breathing's effects are grounded in a well-established body of research on slow, paced breathing. A systematic review by Zaccaro et al. (2018), published in Frontiers in Human Neuroscience, examined fifteen controlled studies and found that slow breathing — roughly six breaths per minute or fewer — consistently increases heart rate variability, activates the parasympathetic nervous system, and reduces self-reported anxiety and stress. At approximately four breaths per minute, the pace of a standard box breathing cycle, these effects are particularly pronounced. The full review is freely available via NIH PubMed Central.

💙 Heart–Brain Coherence

Slow, paced breathing with a longer out-breath, combined with a genuine feeling of gratitude, guides your heart into a smooth, ordered rhythm of around one cycle every ten seconds — roughly 0.1 Hz. Research links this coherent state to greater emotional stability, better stress regulation, and a quieter nervous system.

Three steps

Drop into your heart.

Rest a hand over your heart. Your attention naturally follows touch — wherever you feel contact, awareness follows. This gently moves your focus out of your head and into your heart.

Breathe slow, exhale long.

Breathe so your out-breath is longer than your in-breath. Start wherever feels easy — it should never feel forced. A longer exhale activates your parasympathetic nervous system, telling your body it is safe. Imagine each breath flowing in and out through your heart.

Feel genuine gratitude.

Choose something real — your kids, your family, being alive, a good moment today. Most of the time we feel something only because of what is happening around us; here you are choosing the feeling on purpose. Sustained gratitude settles your heart into a coherent rhythm and brings your heart and brain into sync.

Presets

Gentle

3 s in · 5 s out

Easy starting point

Balanced

4 s in · 6 s out

The 0.1 Hz sweet spot

Deeper

5 s in · 7 s out

For experienced breathers

Tap to try Coherence Breathing
Tip: Many users enjoy layering a gentle binaural beat or soft noise quietly in the background during coherence sessions — try the Calm or Meditation beat, or pink or brown noise, kept low enough that the breath guide and chime stay clearly in front. Both volume controls remain accessible at the top of the page, so you can adjust or turn either off at any point without breaking the session.

The science. The research underpinning this technique comes from HeartMath Institute, who identified and measured heart rate variability (HRV) coherence, and from peer-reviewed work linking slow paced breathing at around five to six breaths per minute (the 0.1 Hz resonance frequency) to increased HRV, parasympathetic activation, and improved stress regulation. The positive emotional engagement step builds on work by McCraty et al. showing that sustained feelings of appreciation reliably shift the nervous system toward a coherent state.

🧘 Body Scan

A body scan is a guided mindfulness practice where you move your attention slowly and deliberately through each part of your body — from the crown of your head to the tips of your toes — noticing sensations as you go without trying to change them. It is one of the most widely studied mindfulness techniques and a core component of Mindfulness-Based Stress Reduction (MBSR), developed at the University of Massachusetts Medical School.

How it works

Most of us carry tension we are not aware of — a braced jaw, raised shoulders, a breath that never quite fully releases. By resting calm, curious attention on each area of the body in turn, the body scan gradually signals to your nervous system that it is safe to let go. You are not trying to relax; you are simply noticing. That noticing — done without judgment — is what allows the body to soften on its own.

How to use it

Find a comfortable position.

Lying down is ideal — on your bed or a mat with your arms resting at your sides. Sitting in a chair works just as well. Loosen anything tight, close your eyes, and settle in before pressing play.

Put on headphones and press play.

The narrator will guide you through each part of your body at a slow, steady pace. There is nothing to do except listen and notice — you do not need to prepare or follow along in advance.

Simply notice what is there.

Warmth, tingling, heaviness, tightness, or nothing at all — all of these are valid. You are not trying to feel something specific. Rest your attention wherever the narrator directs, and observe without judgment.

When your mind wanders, gently return.

Your attention will drift — that is completely normal and not a sign you are doing it wrong. Each time you notice and return your focus to the body, you are practising. There is no failing here.

Stay with it until the end.

The full session is around 15 minutes. You may feel drowsy as your body settles — that is a good sign. If you fall asleep, that is fine too. With regular practice, most people notice they carry less tension through the day.

Tap to open Body Scan
Tip: Many users enjoy playing soft noise or a gentle binaural beat quietly underneath the narration — pink noise, brown noise, or a delta or theta beat can deepen relaxation and mask environmental distractions. Keep the background volume low so the narrator's voice stays clearly in front. Both controls remain accessible at the top of the page and can be adjusted or turned off at any point.

The science. The evidence base for body scan and mindfulness meditation is substantial. A landmark meta-analysis by Goyal et al. (2014), published in JAMA Internal Medicine, reviewed 47 randomised controlled trials and found that mindfulness meditation programmes — of which the body scan is a core element — produce moderate improvements in anxiety, depression, and pain. The MBSR programme, developed by Jon Kabat-Zinn at the UMass Center for Mindfulness, has been widely replicated in clinical settings worldwide. The full Goyal et al. meta-analysis is freely available via NIH PubMed Central.

🌿 Aromatherapy Pairing

Above the player you'll see an Aromatherapy Pairing card that updates as you browse tracks. Each suggestion pairs a specific essential oil with the session you're about to play — certain scents have well-documented effects on alertness, calm, and sleep that complement the audio. It's entirely optional; the audio works perfectly without it.

  • Electric diffuser. Add two or three drops of the recommended oil to your diffuser and switch it on two to three minutes before pressing play. This gives the scent time to spread through the room so it's already present when your session starts.
  • Candle (tea-light) diffuser. Light the tea-light and add two to three drops of oil to the water in the dish. Allow three to five minutes for the heat to release the scent before starting your session. Never leave a candle diffuser unattended, and keep it away from anything flammable.
  • No diffuser. Place one drop on your wrists or the back of your hands, rub together gently, and cup your hands over your nose for a few slow breaths before pressing play. Always use a carrier oil (such as coconut or jojoba) if applying directly to skin, and avoid contact with eyes.

The pairing card can be turned off at any time in Settings → Personalisation → Aromatherapy suggestions.

Tap to try Aromatherapy with Binaural Beats

The science. Aromatherapy works through olfaction — inhaled scent molecules activate receptors in the nasal epithelium that send signals directly to the limbic system, the brain's emotional and memory centre, and the hypothalamus, which regulates heart rate, blood pressure, and stress hormones. Unlike most other sensory inputs, smell has a direct anatomical pathway to these structures, which is why scent can produce fast, involuntary mood and physiological responses. Lavender is the most extensively studied essential oil: a review by Koulivand et al. (2013), published in Evidence-Based Complementary and Alternative Medicine, found robust evidence that lavender reduces anxiety, improves sleep quality, and exerts a calming effect on the central nervous system without significant side effects. Effects vary between oils — peppermint and lemongrass tend to be alertness-enhancing, while chamomile and bergamot lean calming — which is why each audio session is paired with an oil matched to its intended effect. The Koulivand et al. review is freely available via NIH PubMed Central.

✨ Combining Sessions for Deeper Relaxation

You can layer all three tools at the same time for a richer experience. Try this sequence:

  1. Start with Noise Therapy. Pick a background sound — Brown Noise, Pink Noise, White Noise, or Heavy Rain work well — and set the volume low (around 30%). This becomes your gentle base layer.
  2. Add a Binaural Beat. Open the Audio Library and choose a beat that matches your goal — Calm or Sleep for winding down, Focus for deep work. Set it slightly louder than the noise so you can feel it through the background.
  3. Open Box Breathing. Follow the visual guide — breathe in, hold, breathe out, hold. Let the animation set your pace.

Together, the noise softens distractions, the beat shapes your mental state, and the breathing brings your body along. Try it for 10 minutes and notice how you feel.

No wrong way. If three feels like too much, use any two — or just one. The right combination is whichever one you'll actually use.

⭐ Make CRUX Yours

CRUX remembers your preferences so you spend less time setting things up and more time actually using it.

  • Favourite beats and noises. Tap the ♥ heart on any beat card in the Audio Library, or on any noise card in Noise Therapy, to mark it as a favourite. Favourites float to the top of each list automatically.
  • Set what CRUX opens with. Your last-used beat and noise are remembered automatically. To pin a specific starting point instead, open Settings and choose your default beat, noise, and volume under My Defaults.
  • Choose your launch screen. In Settings, set the Launch screen to open straight to the player or the library — no scrolling required.
  • Choose a colour theme. The Appearance section in Settings offers four colour schemes — Air Force, Army, Midnight, and Navy — each inspired by an Australian Defence Force branch. Pick whichever suits your environment or personal preference.
  • Adjust brightness. The Brightness control in Settings dims or brightens the entire interface — useful for low-light environments or before bed.
Everything saves automatically. There is no save button. Close the app, come back later — your defaults will be waiting.

📲 Save CRUX to Your Device

CRUX can be installed like a regular app — no app store required. Once installed, it opens in its own full-screen window, works offline, and your settings are always waiting for you exactly where you left them.

iPhone & iPad (Safari)

  1. Open CRUX in Safari — this does not work in Chrome or Firefox on iOS.
  2. Tap the Share button at the bottom of the screen (the box with an arrow pointing up).
  3. Scroll down in the share sheet and tap Add to Home Screen.
  4. Give it a name (or leave it as-is) and tap Add in the top-right corner.

The CRUX icon will appear on your home screen. Tap it to open — it launches without any browser bars.

Android (Chrome)

  1. Open CRUX in Chrome.
  2. Tap the three-dot menu (⋮) in the top-right corner of the browser.
  3. Tap Add to Home screen or Install app — the exact wording depends on your Android version.
  4. Tap Add when prompted.

Some Android versions will show a pop-up banner at the bottom of the screen asking if you want to install — you can tap that instead.

Desktop — Chrome or Edge

  1. Open CRUX in Chrome or Edge.
  2. Look for the install icon on the right side of the address bar — it looks like a screen with a download arrow, or a circle with a plus sign (⊕).
  3. Click it and then click Install.

If you don't see the icon, open the browser menu and look for Save and share → Install page as app.

Your settings stay private to your device. Everything is stored locally in your browser — nothing is sent to any server, and no one else who uses the same link will ever see your preferences.

⚠️ Safety Information

  • Not medical advice. CRUX is a wellness tool, not a medical device. It does not replace professional mental health care.
  • Do not use while driving or operating machinery. Binaural beats and guided breathing are designed to relax and alter your mental state — always use CRUX in a safe, stationary environment.
  • Keep the volume comfortable. Set your device to a low level before pressing play. Prolonged exposure to high-volume audio can cause permanent hearing damage.
  • Epilepsy and seizure disorders. Do not use binaural beats without first consulting your doctor if you have epilepsy, a history of seizures, or any neurological condition.
  • Stop immediately if you experience discomfort, dizziness, or heightened anxiety.

If you or someone you know is in crisis, help is available 24/7:

See our full Disclaimer for complete safety and liability information.

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