Isochronic tones generator.

The isochronic mode is part of the same free web generator that produces our binaural beats. It is not a playlist of pre-rendered MP3s: the tone is synthesised in real time by the Web Audio API on your own device, so you can set any pulse rate up to 40 Hz and any carrier pitch between 60 and 1000 Hz, and the audio changes instantly. Nothing is uploaded, nothing is recorded, and there is no account to create.

Because the rhythm in an isochronic tone lives in the volume of the signal itself, it survives mono playback. That makes this the mode to reach for when headphones are impractical — a speaker in a shared room, a car, a phone on the desk, or a single earbud. You can also layer white, pink, or brown noise under the pulse from the same screen to soften its character. If you landed here after discovering that binaural beats do nothing on speakers, the full explanation of why — and every honest workaround — is in binaural beats without headphones.

Free sessions run up to 20 minutes, which covers the session lengths most entrainment studies actually use. If you want longer runs, layered ambient sounds, or the 44 preset library, that is what the mobile app is for — but the web tool is a genuine generator, not a demo.

An isochronic tone is amplitude modulation: one carrier tone — say 200 Hz — whose loudness is varied at the target brainwave rate. To aim at a 10 Hz alpha rhythm, the tone swells and dips ten times per second. Unlike a binaural beat, which is an illusion the brainstem constructs from two slightly different tones, the isochronic pulse is physically present in the audio signal before it ever reaches your ear. That is the whole reason it needs no headphones: there is nothing for stereo separation to preserve.

Classic isochronic recordings gate the tone hard on and off — a square pulse with silence between beats. Our generator deliberately uses sinusoidal amplitude modulation instead: the volume follows a smooth wave at the pulse rate, and the modulation depth is partial, so the tone dips clearly but never falls fully silent. Full-depth on/off gating produces the strongest possible rhythm on paper, but many listeners find it abrasive well before the end of a 20-minute session, and a pulse you switch off early does nothing. We chose the version people can actually sit with.

Once the pulsed signal reaches the auditory cortex, the proposed mechanism is the same frequency-following response that binaural beats rely on: cortical activity tends to synchronise with a steady external rhythm. If you want the full pathway from cochlea to cortex, our step-by-step walkthrough of how entrainment works covers it; the isochronic route simply skips the brainstem subtraction step and delivers the rhythm directly.

The links below open the generator with the isochronic mode and pulse rate already set — one tap and you are listening. The rates follow the standard brainwave-band conventions; they are starting points from the entrainment literature, not prescriptions.

Two practical notes. First, because the isochronic pulse is audibly rhythmic — closer to a soft metronome inside a tone than to an ambient wash — it suits daytime and focus use better than falling asleep next to a speaker; if the pulsing bothers you at low rates, layer brown noise under it or switch to binaural mode with headphones. Second, keep the volume low: entrainment does not get stronger with loudness, and a level where you could still hold a conversation is enough.

One safety note applies to all rhythmic stimulation, including this tool: if you have photosensitive or audio-sensitive epilepsy, or any seizure history, talk to a clinician before using pulsed audio.

Here is the part most pages selling an isochronic generator leave out: the evidence for isochronic tones is weaker than the evidence for binaural beats. Not absent — weaker. PubMed indexes more than 200 papers on binaural beats, including randomised trials and a 2019 meta-analysis; the isochronic literature is roughly 30 studies with nothing of comparable weight on outcomes.

What the isochronic side does have is interesting EEG work. Will and Berg (Neuroscience Letters, 2007) measured cortical responses to rhythmic acoustic pulses and found steady-state evoked potentials of larger amplitude than binaural stimulation produced at matched frequencies — the physically-present rhythm drives a stronger measurable response than the reconstructed one. Huang and Charyton's 2008 review of brainwave entrainment reached a similar view: amplitude-modulated stimuli appear to produce robust phase-locking. But a bigger blip on an EEG is not the same thing as a demonstrated benefit, and controlled trials testing isochronic tones against sleep, anxiety, or attention outcomes are scarce. Most isochronic products quietly borrow the binaural evidence base; we would rather tell you the two literatures are not interchangeable.

So the honest framing is this: isochronic tones are a plausible, well-tolerated entrainment method with solid physiological grounding and thin outcome data. They are a complementary wellness tool, not a treatment for insomnia, anxiety, ADHD, or anything else — and the practical case for them is mostly logistical: they are the mode that works when headphones do not. The full comparison, including where each method genuinely wins, is in our binaural beats vs isochronic tones breakdown.

A simple decision rule covers almost every case. If you can wear stereo headphones and your goal is sleep, meditation, or winding down anxiety, start with binaural mode — it is smoother to listen to and carries the larger research base. If you are on speakers, sharing the room, using one earbud, or you simply find the binaural carriers fatiguing, use isochronic mode: it is the only one of the two that still works at all in those situations.

You do not have to commit. The generator switches between binaural, isochronic, and pure-tone modes mid-session without stopping the audio, so the cheapest experiment is to try both at the same pulse rate and keep whichever your ears prefer.