Dec [{()}]1d ago

Skoda developed (with the University of Salford) an all-mechanical bicycle bell that bypasses active noise cancellation (ANC) in headphones.
https://www.skoda-storyboard.com/en/skoda-world/skoda-duobell-a-bicycle-bell-that-outsmarts-even-smart-headphones/
It's tuned to 750hz, which is a "blind spot" in most ANC headphone processing.
There is also a resonator for a higher frequency, and the hammer produces irregular strikes, confusing the ANC further, and making pedestrians look behind them faster.

Video:
https://www.youtube.com/watch?v=zDaVPfpQvPI

Research:
https://cdn.skoda-storyboard.com/2026/04/Skoda-DuoBell-Research-final_cf127752.pdf

#BikeTooter

Škoda DuoBell: A bicycle bell that outsmarts even smart headphones - Škoda Storyboard

Pedestrians wearing headphones are exposed to an increased risk of accidents. In an effort to reduce collisions with cyclists, Škoda Auto, in collaboration with scientists, introduces an innovative bicycle bell whose sound can penetrate even active noise cancellation systems. In doing so, it helps prevent injuries to both pedestrians and cyclists.

Škoda Storyboard
Show threadMoz1d ago

@dec23k that is very cool. But I can't buy one!! Hopefully people start manufacturing them because the noise cancelling problem exists in Sydney, Australia as well.

#SkodaDuoBell #DuoBell #BikeTooter

Show threadDec [{()}]1d ago

@moz
It should be possible to build a simple battery-powered electronic 'horn' that pulses a tone around 750hz, and another tone in the typical 'bell' range.

I have a few ways of generating 750hz from a portable device, but no noise cancelling headphones (of my own) for testing.

Show threadSupermoosie1d ago

@dec23k @moz

Or a 115 decibel bike air horn will just over power their headphones, make them jump 4 ft in the air and shit themselves.

https://www.ansco.com.au/air-zound-xl-bike-horn-pet-cannister

Air Zound XL Bike Horn

AirZound is a loud 115db, the Air Zound Bike Horn refills quickly and easily with a bike pump or compressor.

www.ansco.com.au
Show threadDec [{()}]1d ago
@SuperMoosie @moz
Crikey!
But also, that does look like it's intended for use in mostly vehicle traffic.
Show threadMoz

@dec23k @SuperMoosie yes, they target motorists. But they also work on other vehicles, and on pedestrians.

Air Zounds use a standard soft drink bottle cap, so you can replace the bottle it comes with with a 2l or 3l soft drink bottle. And if you're BikeSaint, pour the soft drink down a drain :) It's worth covering the bottle with tape or something just in case it gets damaged and shatters.

3l gives you quite a lot of tooting, but takes quite a lot of bike pumping action to fill

Apr 8 at 10:18amWeb
Show threadDec [{()}]1d ago
@moz @SuperMoosie
I like that sustainable design decision, and I admire your dedication to research!
Show threadSupermoosie1d ago
@moz @dec23k
I used to recharge mine the local servo air pump.