Škoda's DuoBell Bicycle Bell Engineered to Penetrate Noise-Cancelling Headphones

Czech automaker Škoda Auto has developed the DuoBell, a mechanical bicycle bell designed to be heard through active noise-cancelling (ANC) headphones. The device rings at a precise 750 hertz frequency, targeting a narrow 'safety gap' in ANC filters identified through research with the University of Salford. This mid-frequency range, between 750 and 780 hertz, consistently penetrates the technology. Škoda design head Oliver Stefani described it as a simple, analogue solution to a digital problem. The innovation aims to address a growing safety concern, citing London where bike-pedestrian collisions rose 24% in 2024, with ANC headphones as a contributing factor. The bell incorporates a second, higher frequency resonator and a special striking mechanism that creates rapid, irregular impacts to further fool ANC algorithms. Virtual reality and real-world tests, including with Deliveroo riders, found the DuoBell could be heard up to five seconds earlier and 22 metres further away than standard bells. Škoda has made its research freely available in a white paper to encourage broader adoption. The project involved creative agency AMV BBDO, PHD Media's innovation team, and production company Unit 9. Škoda, which began as a bicycle manufacturer in 1896, continues to support cycling through its We Love Cycling platform.