Škoda has designed a bicycle bell that can be heard even by people wearing noise-canceling headphones.

The Škoda DuoBell is a new bicycle bell developed in collaboration with acoustics experts from the University of Salford. The design is entirely mechanical, with no electronics, yet it allows the bell to "pierce" the active noise cancellation (ANC) algorithms in modern headphones.

The conventional bicycle bell hasn't changed in over 100 years, but the streets have. According to official data, the number of collisions between cyclists and pedestrians in London increased by 24 percent in 2024 alone. One key factor is the widespread use of ANC headphones. Up to half of pedestrians on London's streets use such headphones, and many models block external noise so effectively that a standard bicycle bell simply cannot be heard.

ANC works by detecting external noise and generating an opposite sound wave to neutralize it. The technology handles uniform, low-frequency sounds well, such as the hum of an airplane or air conditioner, but it has vulnerabilities.

Researchers at the University of Salford discovered a narrow frequency range of 750 to 780 Hz that noise-canceling algorithms cannot consistently suppress. This range became the basis for the DuoBell.

The bell features two resonators: the first is tuned to the ANC "blind spot" in the 750–780 Hz range, while the second is tuned to a higher frequency, closer to the sound of a conventional bell. Additionally, a special striking mechanism delivers frequent and irregular impulses. This combination generates sound waves that noise-canceling algorithms simply cannot process quickly enough.

Tests in virtual reality environments and on real London streets showed that pedestrians using ANC headphones heard the DuoBell 22 meters earlier and five seconds sooner than a conventional bell. Real-world testing involved Deliveroo couriers, and according to Škoda, after the trials, they wanted to keep the bells for themselves.

For now, the DuoBell remains a concept, not available for sale, and is not expected to be in the near future. However, Škoda does not plan to keep the development behind closed doors; instead, it intends to publish the results of the acoustic research so that any bicycle bell manufacturer can use this knowledge.

This significantly distinguishes the DuoBell from a typical corporate PR project. If the data truly becomes public, the technology could appear in mass-produced bells.

The fact that a Czech car manufacturer decided to tackle a bicycle bell may not seem so surprising when you consider that over 130 years ago, Škoda began by manufacturing bicycles. The company remains active in cycling, serving as the official partner of the Tour de France, La Vuelta, Paris–Roubaix, and Liège–Bastogne–Liège, and in 2026, it also became a partner of the International Cycling Union (UCI) for the Mountain Bike and Gravel World Championships.