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: 0.11.0
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.
Study, then play
The 7 rhythms in this demo, each drawn as one still cycle: filled shapes are pulses, empty space is quiet, and every drawing shares one seconds scale. Study a row, play it, then take the quiz.
Every timing below is read from the published vocabulary at run time. None of it is typed onto this page.
Answer the light warning above, and a Play button appears on every row.
WATER
long, rolling pulses that keep coming
Covers: flood, tsunami, storm surge
6.0s cycle · 2 pulses · light and sound at 100%
FIRE
ten fast pulses, nothing else is this fast
Covers: fire, wildfire
4.0s cycle · 10 pulses · light and sound at 100%
GROUND
one long pulse that does not let go
Covers: earthquake, landslide
4.0s cycle · 1 pulse · light and sound at 100%
STORM
three sharp pulses
Covers: cyclone, typhoon, tornado, severe storm
4.5s cycle · 3 pulses · light and sound at 100%
THREAT
a knock, a long push, rapid fire, then a full stop
Covers: danger from people (attack, active threat, missing child)
6.3s cycle · 7 pulses · light and sound at 100%
TEST
a gentle double tap, then a long quiet: checking, not warning
Covers: test or drill, never a real emergency
8.2s cycle · 4 pulses · light and sound at 30%
ALL CLEAR
one soft press easing away, a short settling one, played once
Covers: the danger has ended (an affirmative, authenticated update)
2.4s cycle · 2 pulses · light and sound at 25% · plays once
Danger has a rhythm. Safety lets go.
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.