A new bike bell designed to cut through noise-cancelling headphones could help prevent collisions on busy city streets, following groundbreaking research involving acoustic experts in Salford.

Working alongside car manufacturer Škoda, researchers at the University of Salford have developed the “DuoBell” — a redesigned bicycle bell engineered to be heard even by pedestrians wearing active noise-cancelling (ANC) headphones.

The innovation comes amid rising concerns over urban safety, with figures from Transport for London showing bike–pedestrian collisions increased by 24% in 2024. At the same time, cyclists are expected to outnumber drivers in London for the first time this year.

Unlike traditional bells, the DuoBell targets a specific frequency range that ANC technology struggles to block. Researchers identified a narrow “safety gap” between 750Hz and 780Hz — a band of sound that consistently slips through noise-cancelling filters. As a result, the new bell can be heard up to 22 metres away and as much as five seconds earlier than standard designs.

Dr Will Bailey, an acoustics expert at the University of Salford, said the project revealed how modern listening habits are reshaping public safety.

“This project uncovered something fascinating about how we experience sound in modern environments,” he said. “We’re proud to have worked with Škoda to turn that insight into something practical that could make a real difference to safety in our cities.”

The DuoBell also uses a second resonator tuned to a higher frequency, alongside a striking mechanism that creates rapid, irregular sound patterns — effectively “confusing” ANC algorithms so they cannot cancel the noise in time.

The bell has already been trialled in real-world conditions, including a two-week test with riders from Deliveroo. Feedback from couriers helped refine the final design, with one rider saying the device meant he “finally had a voice in the streets”.

Developed in collaboration with creative agency AMV BBDO, media agency PHD, and production company Unit 9, the DuoBell represents what Škoda describes as “an elegant analogue solution to a digital problem”.

The company has also released its research as an open-source whitepaper, encouraging wider adoption of the technology across the cycling industry.

Meredith Kelly, Head of Global Marketing at Škoda, said: “This project is a great example of how a simply clever idea can help make that exploration safer for everyone.”

With the rapid rise of noise-cancelling headphones changing how people interact with their surroundings, the DuoBell could mark a significant step forward in keeping both cyclists and pedestrians safe on increasingly crowded city streets.