Under Hemi-Sync are binaural beats.
Here, you can shape them.
Hemi-Sync is a trademarked name for one way of layering binaural beats. The idea underneath belongs to no one. Shimmr makes binaural beats live on your iPhone or iPad, and lets you move, mix and save them.
What’s the same idea
A tone in each ear
Play 200 Hz in one ear and 204 Hz in the other, and your brain hears a soft 4 Hz beat. That effect, described in 1839, is what Hemi-Sync builds on. You need headphones for it.
A name for a method
Hemi-Sync is short for hemispheric synchronisation. Robert Monroe wrote that he coined the name, and a 1994 patent describes his way of layering beats, pink noise and voice.
Slow beats to settle
The clearest public example of Hemi-Sync uses 4 Hz beats, at the edge of Theta and Delta, the zone of drowsiness. Shimmr has sessions in every band, from Delta to Gamma.
Headphones on, eyes closed
You listen the same way: lie down, keep the volume low and give the sound time to work.
What you can do here
Shifts that glide
The beat moves from where you are to where you want to be, then holds. Tense → At Ease glides from Beta to Theta in 15 minutes. Awake → Asleep goes from Alpha to Delta.
Isochronic for speakers
Isochronic sessions pulse a single tone on and off, so they work without headphones. They run from Delta to Gamma.
Sound Canvas
Drag a tone around a space and hear its beat change live while it plays. Add rain or noise, then save what you build.
A mixer under every session
Set the levels of tones, ambience, noise and your own music. Add pink or brown noise, reverb, high cut or EQ, and save the mix.
Journeys, if you want a voice
Guided sessions through weight, breath and sound, with the tones moving underneath. Choose Soft, Balanced or Clear, or turn the voice off.
Hemi-Sync recordings vs Shimmr
| Hemi-Sync recordings | Shimmr | |
|---|---|---|
| Who makes it | Robert Monroe’s method, used in Monroe Institute recordings | An independent app, made in Stockholm |
| The sound | Fixed recordings | Generated live on your device |
| The beats | Several beats layered at once, with pink noise to mask the tones | One beat per session, or a beat that glides in a Shift; in Sound Canvas you see each tone and where it sits |
| Voice | Spoken guidance and affirmations on many recordings | Only in Journeys, and you can turn it down or off; Shifts have none |
| Adjust | You play the recording as it is | Mixer for levels, noise, ambience, reverb and EQ; Sound Canvas to change a beat live |
| Platforms | Recordings, and the Monroe Institute’s Expand app on Apple devices and Android | iPhone and iPad |
Hemi-Sync details from Monroe’s 1994 patent and a 1983 US Army assessment. Platforms as of November 2026.
Shifts
Named by the change, not the sound. The beat glides, then holds where you want to be. No voice.
- 1 Tense → At Ease Beta to Theta. For when your shoulders are up and your thoughts won’t stop.
- 2 Awake → Asleep Alpha to Delta. Set how long you have, and the beat gets you there on time.
- 3 Busy → Quiet Beta to Alpha. A short way down after a full day.
- 4 Scattered → Focused Theta to Beta. From drifting to ready to work.
- 5 Flat → Bright Alpha to Beta. A lift in the afternoon.
Hear the sound
Thirty seconds of Tense → At Ease, which needs headphones, and an isochronic Theta session that plays on speakers. Both made live by the app.
To be clear
Shimmr is not Hemi-Sync and is not linked to the Monroe Institute. It has none of their recordings and does not reproduce their signals or Focus levels. Official Hemi-Sync recordings are sold at hemi-sync.com. Shimmr is a way to try binaural beats, the idea underneath, built independently.
Questions
Is there a Hemi-Sync app?
The Monroe Institute makes its own app, Expand, and its release notes say the timer soundscapes include original Hemi-Sync tracks. Shimmr is a separate, independent iPhone and iPad app that makes binaural beats live, with no Hemi-Sync recordings.
Is there a free alternative to Hemi-Sync?
Shimmr is free to download, and its first guided journey, Arrival, is free for everyone. It uses binaural beats, the idea Hemi-Sync is built on, not Hemi-Sync itself.
Is Hemi-Sync just binaural beats?
The sound underneath is binaural beats. Hemi-Sync layers several beats with pink noise and often a voice, and claims the two halves of the brain fall into sync, which research has not established.
Does Hemi-Sync work?
Some people find it deeply relaxing, but the evidence is modest and mixed. A 2023 review of 14 EEG studies found that brainwaves followed binaural beats in some studies and not in others.
Does Shimmr use Hemi-Sync?
No. Shimmr has no link to the Monroe Institute or Hemi-Sync, and it does not reproduce Hemi-Sync signals or Focus levels. Its binaural beats are generated from scratch on your device.
Hemi-Sync and Gateway Experience are trademarks of their owners. Shimmr is not a medical device. Never listen while driving. If you have epilepsy, ask your doctor first.
