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

@dec23k

So, in the use-case scenario here, I'm on my bike, and I see that there's a person walking/wheeling ahead of me and they're wearing noise cancelling headphones.

Question:

Why do I need a bell?

Assumptions:

(a) If they're ahead of me and in my path, I'm either on a footpath, shared path, or carriageway;

(b) I have seen them.

Answers:

(b) I have seen them;

(a) If I'm on a footpath, I need to move; if I'm on a shared path, I need to wait; if I'm on a carriageway, I need to wait.

@clickhere @dec23k My use case for bells is that there are people ahead of me walking in the road, and I want to let them know I'm there when I'm far enough away that I won't startle them when passing politely (assuming it is safe to do so). Some people prefer a bell to a call -- sometimes a bell announces "bicycle" rather than "runner" in a way people prefer.

I don't cycle on paths or the pavement.

@ravenbait @dec23k Oh yeah, in general, I use a bell now and then, in a fairly similar way.

But if I see that someone has noise cancelling headphones - or otherwise doesn't seem to have reacted to the sound of the bell (they may be deaf or hard of hearing) - then I'll adjust what I'm doing. (Like, I won't barge past, usually just take my time and wait for an opportunity to pass safely.)

But this over-engineered, highly specific use-case? Nah.

@clickhere @ravenbait
I just saw something vaguely interesting in a video, and saw that nobody on Fedi had written about it. So I wrote something on Fedi about it, and then more than 100 accounts liked or boosted it.

The video has quotes about "working with partners" in London, and "sharing this with the world", but Skoda seem to have only made enough bells for the field test, and aren't trying to sell them.

Maybe they just want more people to be aware of Škoda's bicycle-manufacturer origins?

@dec23k @clickhere It's weird, isn't it? It's basically stealth marketing. I wonder who the audience is.

@dec23k @clickhere Or who the *intended* audience is, I should say.

Full disclosure: we have a car chez Ravenbait, and it is a Skoda. Other than it being a reliable workhorse that is relatively cheap to repair, I have no allegiance.

@ravenbait @clickhere
Full disclosure: I have never owned a car, and I no longer own a bicycle (was a daily rider until I had 4 stolen in the same 12 month period when I was living between the canals). Getting around mostly on foot and on public transport. Never had the car brain, but the rothar brain is still strong.

I also don't own any ANC headphones, so I can't test for any possible "blind spot" frequencies.

@dec23k Full disclosure: I'm multi-modal.

(oo-er)

Although, tbf, my motorised mode was years ago and a Vespa, but it counts. (I *can* also drive a car, just not well or legally. Maybe I should get one!)

@ravenbait

@ravenbait @clickhere
And now there's a yt-short video about it from renowned mathematician Hannah Fry.

@dec23k Ker-ching!

Yeah, Skoda have been leaning into the cycling buzz a fair bit over the years, so this could be more marketing, all right.

I mean, I think it is interesting as an exploration of the physics, etc., but not so sure about the bike bell application - maybe emergency warnings in public places, or something?

I must take a look at Fry's video, though, love her. She's such a nerd, and such a great communicator for normies like me.

@ravenbait

@clickhere @dec23k I'm certainly not the right market for their bell -- I have a couple of very loud, sustained, but discreet bells that I bought for their minimal handlebar real estate and delightful sound. That thing looks like you could use it as a life preserver if you fell in a canal! I will give them points for trying to build a bridge between motorists and cyclists, though, because we sorely need bridges.