Clever Bike Bell Penetrates Noise-Canceling Headphones
- 3 hours ago
- 2 min read
The Škoda DuoBell bicycle bell is an excellent example of a completely analog solution to a safety problem caused by digital innovation.
People wearing headphones using active noise cancellation are often left in a perceptive bubble where they fail to react - or simply react too late - to imminent dangers on streets and sidewalks they can't hear coming. The team behind the DuoBell have figured out how to make the bell's ringing sound bypass the noise-canceling capabilities of modern headphones.
Researchers from the Czech brand Škoda - best known for its cars, but actually made its commercial debut in 1895 with a bicycle - worked closely with researchers at England's University of Salford to come up with a way to overcome active noise cancellation (ANC).
They discovered something that they call the “safety gap,” located in the frequency range between 750 and 780 Hz. Sounds within this frequency range can reach the ears of people using ANC headphones; the cancellation systems are unable to adequately create counter-phase sound waves to mask noises within this narrow frequency range.
The structure of the bell is completely mechanical, but it also includes an additional resonator tuned to a higher frequency to improve the bell's overall efficiency. The hammer mechanism also generates rapid blows. This is ideal for city environments when more than one ding is often necessary to get someone's attention, but it's also integral to the design because the rapid, irregular dings are harder for ANC systems to cancel out.
There's currently no information about pricing and availability, but - when released - it's likely to become a powerful new early warning device. Particularly as, during real-world tests on London's busy streets - people wearing ANC Headphones were able to detect an approaching cyclist ringing the bell five seconds and 22 meters earlier than cyclists with a conventional bell.
