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The Three Senses Alerting Standard

Feel the rhythm

This is not a mock-up. Tap a hazard and the whole screen plays that hazard's rhythm, on the timings published in the standard. Where the phone supports vibration, your hand gets the identical rhythm from the same clock. Then try guess mode: watch one rhythm with no label, and see whether you can name the danger before the answer appears.

Vocabulary version: 0.10.3

Flashing light ahead

The next screen can fill your display with flashing light. If flashing light is a problem for you, choose the steady option: it never modulates the light at all.

FIRE and THREAT are the two rhythms that reach the ceiling: both hit three flashes in their worst single second, and neither ever exceeds it. FIRE also has the fastest sustained flicker in the vocabulary, two and a half flashes per second across its whole cycle. Three flashes and six state changes per second is the ceiling the standard sets, drawn from WCAG 2.3.1, and this page checks every rhythm against it in your browser before it plays anything.

The 7 rhythms in this demo

Every timing below is read from the published vocabulary at run time. None of it is typed onto this page.

  • WATER

    flood, tsunami, storm surge

    Waves keep coming: long soft rolls, a breath apart, like the rolling hand motion of the signs for waves. The cadence is steady under looping.

    6.0s cycle · 2 pulses · light and sound at 100%

  • FIRE

    fire, wildfire

    Flames flicker fast: ten rapid pulses, like the fingers of the sign for fire flickering upward. Nothing else is this fast. 2.5 flashes per second, inside the 3 per second bound, and the flicker stays exactly 2.5 per second across the loop boundary.

    4.0s cycle · 10 pulses · light and sound at 100%

  • GROUND

    earthquake, landslide

    The ground does not pause: one long unbroken hold, like the sustained-shaking signs for earthquake. Looped, it fuses into one continuous shake. Nothing else is unbroken.

    4.0s cycle · 1 pulse · light and sound at 100%

  • STORM

    cyclone, typhoon, tornado, severe storm

    Wind arrives in gusts that slam: a sharp knock every one and a half seconds, steady under looping.

    4.5s cycle · 3 pulses · light and sound at 100%

  • THREAT

    danger from people (attack, active threat, missing child)

    A human threat announces itself: one hard knock at the door, one long push, five rapid fires, then a full stop. The stop is long enough that the next knock lands out of real silence. A sequence nothing natural makes.

    6.3s cycle · 7 pulses · light and sound at 100%

  • TEST

    test or drill, never a real emergency

    A quick gentle double tap, a long quiet, then the double tap again: checking, not warning. A drill must never feel like an emergency.

    8.2s cycle · 4 pulses · light and sound at 30%

  • ALL CLEAR

    the danger has ended (an affirmative, authenticated update)

    The release: one long soft press easing away, a real breath, a short settling press. Like a breath out, easing pressure meaning done (protactile-native). A hypothesis under human testing, like all mimesis claims.

    2.4s cycle · 2 pulses · light and sound at 25% · plays once

The Three Senses Alerting Standard is an open rule set from International Deaf Emergency: one shared rhythm for all, rendered identically on touch, light and tone, with the full warning in accessible language. It is publicly available and royalty-free, and it is offered to regulators.

Even a plain SMS can drive these rhythms: 3S:W4

Rhythms and code in this demo come from the published vocabulary, Apache-2.0.