If you’ve ever cycled through a busy city and watched someone step out in front of you, headphones firmly in place, you’ll understand the problem Škoda is trying to solve. The DuoBell is a redesigned mechanical bicycle bell developed in partnership with researchers at the University of Salford, and it’s built specifically to be heard by people wearing active noise-cancelling headphones.
It sounds almost absurdly niche until you consider how many people now wear ANC headphones while walking, running, or just zoning out on a commute. In cities like London, the mix of rising urban cycling numbers and increasingly effective noise-cancelling technology has created a genuine road safety gap. A standard bike bell simply doesn’t register for someone whose headphones are actively filtering out the world around them.
How the DuoBell actually works
The engineering behind it is more interesting than you might expect. Researchers identified what they’re calling a “safety gap” in ANC performance, a narrow frequency band sitting between 750 and 780 Hz where most noise-cancelling algorithms consistently struggle to suppress sound. The DuoBell rings within exactly that range, essentially slipping through the filter rather than fighting it.
That’s just the first part. The bell also features a second resonator tuned to a higher frequency, which keeps it sounding like a recognisable bike bell to the human ear rather than something clinical or unfamiliar. Then there’s the striking mechanism, which produces rapid, irregular bursts rather than the steady single ring of a traditional bell. ANC processors work by predicting and cancelling incoming sound patterns, and those irregular strikes are too fast and too unpredictable for the algorithm to catch up with in time.
Three things working together, then: the right frequency range, a dual resonator to preserve the familiar sound character, and an unpredictable strike pattern that ANC can’t get ahead of.
What the testing showed
Real-world trials were run with Deliveroo couriers in London, putting the bell into daily use rather than just a controlled lab environment. The results were significant enough that riders reportedly wanted to keep using it on their own bikes after the trial ended, which is probably the most honest endorsement you can get.
In those tests, pedestrians wearing ANC headphones were able to detect the DuoBell from up to 22 metres further away than they could hear a standard bell. That extra distance translates directly into reaction time, giving both the cyclist and the pedestrian more space to respond before a potential collision.
Analogue solution to a digital problem
Škoda is positioning the DuoBell as an analogue fix to a digital problem, and there’s something genuinely clever about that framing. Rather than adding electronics or connectivity to a bicycle bell, they’ve gone the other direction, using acoustic engineering to update a century-old safety device so it works within the constraints of modern listening habits.
The prototype follows Škoda’s Modern Solid design language and carries the company’s current branding. Škoda has a long history in cycling that often gets overlooked alongside the cars, and the DuoBell fits neatly into that side of the brand.
Perhaps most notably, Škoda has made all of the research and findings publicly available at no cost, meaning any manufacturer can use the findings to build their own version. That open approach suggests the goal here is genuinely about pushing the safety idea forward rather than locking it down as a product.
