If you’ve searched for isochronic tones on YouTube or any productivity app, you know what it is like: an audio recording that plays on a loop. Forty minutes of something pulsing at a certain frequency, a sound file that someone produced at some point.

And it works in some ways (saying otherwise would be a lie), but it could work way better.

For starters, an isochronic tone designed in the traditional way has a structural limitation that often gets overlooked: It’s a loop.

It was recorded once at a fixed frequency under particular conditions, so it plays back exactly the same way every time. Same frequency at nine in the morning as at eleven at night, same file on your first working minute as when you’re three hours into your fifth session.

The audio knows nothing about you, only how to play.

Mind Focus does something different and it makes sense to explain what and why.

For starters, the tones are not prerecorded and looping, they’re generated on the fly.

Every time you start a session, the app synthesises the tone in real time. There’s a carrier oscillator (the sound frequency you hear) and an LFO (Low Frequency Oscillator) that modulates its amplitude at the corresponding rhythm.

All of this is done mathematically on the fly, there’s no prerecorded file involved.

The tone simply exists continuously, for as long as your session lasts.

But it doesn’t just exist as is, it adapts…

Warm-up and habituation ramps for the brain

A prerecorded isochronic tone plays at the same frequency from the first second to the last. You press play and you’re already at 18Hz, 40Hz… whatever it is.

But the brain doesn’t work that way.

Wave synchronisation (the underlying mechanism by which isochronic tones work) is a gradual process, not an instantaneous one, which is why the app also behaves that way.

Jumping straight to the target frequency is like starting to run at full speed without warming up.

Mind Focus starts at a lower frequency and gradually rises to the target over the first few minutes of the session.

Depending on the mode, the ramp duration varies, adapting to the session at both ends, since it acts in the same way when the session is near its end. In that moment, the tone descends gently rather than cutting off.

So the beginning and the end are transitions, not interruptions, mirroring how our brain works.

But don’t go anywhere yet, here’s more.

The tones know what time it is (seriously)

This is the detail I like most and no other app uses it either, mainly because a recording doesn’t know what time it is, or they haven’t looked closely enough at the underlying mechanism to replicate it optimally in their apps.

The science of circadian rhythms has spent decades documenting that the brain doesn’t function the same way throughout the day.

The «beta» alert state is a natural occurrence in the morning, when we’re most awake and, hopefully, most rested after the night. However, by mid-afternoon SMR waves (SensoriMotor Rhythm) predominate, and they are associated with sustained attention without overactivation.

At night, the brain no longer feels like working and tends towards alpha frequencies, more appropriate for calm concentration, reading, some creative work…

As with everything in life, there are always night owls and people with different biorhythms due to genetics and so on, but in general, humans are diurnal, cyclical, and follow those general patterns.

Ignoring this is working against yourself, reducing the effectiveness of concentration through isochronic tones or other external techniques, which is why I wanted a generation algorithm that took all of this into account.

This way, Mind Focus adjusts the frequencies according to the time of day, alternating Beta, SMR, and so on.

I’m afraid I can’t reveal the specific «secret sauce» for intelligent generation in full, but the key is that it’s not the same session every time, it’s the one optimised for the moment.

The Ultrafocus exception

Ultrafocus mode generates Gamma tones, the wavelength associated with high-demand cognitive processing. It’s the frequency that activates when the brain is working on something truly complex and, therefore, it’s not a mode for constant daily use.

That’s why it operates separately with its own audio management. In this case, I concluded that when you need Ultrafocus-level concentration, you need it and that’s that, so Ultrafocus mode ignores the time of day and biorhythm and operates at full power.

That’s why it’s not always advisable, especially in the afternoon or evening, because in some cases it can put us in a state of alertness that makes it slightly harder to wind down or rest afterwards.

But let’s be honest, sometimes life demands it, and that momentary extra is required.

Brown and pink noise

The background noise that can accompany the tones if you wish (brown or pink, depending on the mode) is also not a prerecorded file.

Again, it’s generated directly in the device’s audio processor mathematically and with the same criterion as the tones: no cuts, no audible loops, continuous throughout the entire session.

A recorded tone does the same thing always. A tone generated intelligently as in Mind Focus can adapt to the time, the mode or the phase of the session. It can enter smoothly and exit the same way when it’s time to finish. Just as it knows whether you’re at minute three or minute forty and sounds different in each case.

That’s the big difference.

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P.S. That said, this doesn’t end here. In my personal version of the app (that I’m developing continuously) I’m further optimising the generation of tones and their nature so, if the tests go well, future versions will improve this whole area of tones and generation even more, in line with the latest evidence.