This bicycle bell could literally save lives. In London, about 1.5 million people cycle to work, and more and more pedestrians are wearing active noise-cancelling headphones. As a result, they simply don't hear approaching bicycles, and the number of collisions between cyclists and pedestrians has increased by 24%.
Then Skoda came up with an unexpectedly simple yet clever solution: the fully mechanical DuoBell bicycle bell. Engineers tested hundreds of sounds and six popular models of ANC headphones to find the frequency that noise cancellation blocks the worst. They discovered a "safety window" of around 750 Hz and tuned the bell to precisely this range, adding a second frequency to enhance the effect.
As a result, this dual-tone bicycle bell sounds approximately 22 meters earlier than a standard one—almost 5 seconds faster. This is enough time for a pedestrian to move away and for a cyclist to avoid a collision.
And the coolest thing is that Skoda has made the entire study publicly available. Sometimes true innovation is simply about keeping people safe.