If you use the Moscow metro, you probably noticed these boxes in front of the doors of some stations that make strange sounds.
At first, like many others, I thought that these were passenger counters. But the device periodically makes a sound even if there are no passengers.
The sound is like this:
https://www.youtube.com/watch? v=Ccz2z_BM8_E
It turned out that these are sound beacons that help the blind find the entrance to the subway. The beacon emits a characteristic sound every ten seconds and changes its volume depending on the level of ambient noise.
Beacons are installed at 45 stations.
Found even news about these lighthouses on the metro website.
Peace for everyone!
© 2022, Alexey Nadezhin
For twelve years I have been writing about technology, discounts, interesting places and events. Read my blog site ammo1.ru, in Learn, Zen, Mirtesen, Telegram.
My projects:
lamptest.ru. I test LED lamps and help you figure out which ones are good and which are not so good.
Elerus.ru. I collect information about domestic electronic devices for personal use and share it.
You can contact me in the Telegram group @ammochat.
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