DuoBell

Škoda has unveiled Škoda DuoBell, the first-ever bike bell designed to penetrate noise-cancelling headphones, trialled by Deliveroo riders. A game-changer for urban safety, it has the potential to help cyclists be heard in cities again. An elegant analogue solution to a digital problem, the bell has reinvented a 100-year-old safety device for the noise-cancelling generation.
In London, cyclists are set to outnumber car drivers for the first time this year. But bike–pedestrian collisions also rose by 24% in 2024, according to Transport for London data. One contributing factor is the widespread rise in the use of noise-cancelling headphones. Active Noise Cancellation (ANC) reduces awareness of approaching cyclists, posing serious danger to pedestrians and cyclists.
Developed in partnership with creative agency AMV BBDO, PHD Media's innovation team, and production company Unit 9, Škoda’s response is a smart engineering solution: a mechanical bell that fools ANC algorithms.
Researchers and acousticians from the University of Salford worked with Škoda to conduct one of the world’s first studies examining how ANC technology affects the audibility of traditional bicycle warning bells. Active Noise Cancellation (ANC) works by generating counter-sounds that cancel incoming audio signals, meaning everyday alerts, including traditional bike bells, can be filtered out before reaching the listener.
Through acoustic testing, the research team identified a narrow frequency band, or “safety gap”, of between 750Hz and 780Hz' that consistently penetrates ANC filters. As a result, the new DuoBell can be heard up to 5 seconds earlier and up to 22 meters further away than a standard bike bell*.

By combining this with a second resonator tuned to a higher frequency, and a specially designed striking mechanism that produces rapid, irregular impacts, the bell generates sound waves that are designed to fool the ANC algorithms.
Setting a new bike bell design standard, Škoda’s DuoBell is designed to be simple and affordable to manufacture.
The bell has been tested to achieve efficiency through real-world trials with partners operating in busy urban environments. A two-week trial using a fleet of Deliveroo riders who depend on road safety daily was also completed. By providing feedback from their daily on-road use, the riders helped to shape the final prototype. One Deliveroo rider championed the DuoBell, saying that with the tech, “he finally had a voice in the streets”.
Trials found that pedestrians wearing ANC headphones had as much as 5 seconds earlier and up to 22 meters to react when the bell was activated, providing a critical safety margin*.
As part of the initiative, Škoda has shared its findings in an open-source whitepaper, using research as a public service to help make cities safer.
An influencer-led awareness campaign featuring Professor Hannah Fry and delivery driver London Hustle also runs throughout April across social media channels, with additional content launching later in the month.
Škoda’s cycling heritage dates back over 130 years, having started life as a bicycle manufacturer in 1895. Today, the Czech brand continues to champion cycling globally and supports dozens of international cycling events, including La Vuelta, the Tour de France Femmes, and, for more than twenty years now, the Tour de France.