Thursday, December 27, 2012

The best bicycle horn sounds like a car

Part 2/2, see Part 1.

As a cyclist you are immersed in the environment; you can hear leaves crumple under your wheels, feel the breeze on your skin and detect the tiniest imperfections in the pavement. Your eyes constantly scan the road looking for cars that might veer into your path. When you see such a car, take a deep breath, because if the car starts to veer - you’d better hope they hear you screaming. The Loud Bicycle horn is a far better option; let me explain why.

Honking is an effective way to stop a car crash
Biking safely and responsibly are the most important things you can do to stay safe on the roads; but when there is an emergency, honking a car horn is your best option to stop an imminent accident.

Drivers ears are tuned to pick up the sound of a car horn above the bustle of noisy roads and any musical distractions, just like you recognize your name at a cocktail party. But, more importantly, drivers react better to the sound of a car horn than to other warning sounds [source]. This means that biking with a Loud Bicycle car horn will help you avoid accidents in a way that just isn’t possible with other bicycle horns.

There are so many other reasons why ours is the best horn to help protect you on a bike that I need to put them in a list:

  • Our brains are really sensitive to a multi-note car horn sound. Dr. Shinn-Cunningham, my former professor and Auditory Neuroscience Lab director at Boston University explains “Modulated sounds (like when two notes beat) are more attention-getting than steady-state sounds.”
    Although the Loud Bicycle horn isn’t the loudest on the road, the modulated sound is the best way of grabbing the attention of a driver.
  • In a collision-warning context people react to the sound of a car horn incredibly fast. One study from the University of Western Sydney showed that "without training, participants recorded significantly faster reaction times in response to auditory icons [car horns] compared with other signals" [source]. Another study lists car horns among the sounds that people react most quickly to even without a specific context [source].
  • The two, relatively-low frequencies of a car horn make it easy to localize where the sound is coming from. And, more importantly, drivers actually use that information, showing "a significant performance advantage in the detection of potential emergency visual driving events ... when [hearing a car horn] coming from the relevant direction”
  • Lower pitched sounds like those of car horns travel far, even at low volumes; they can also penetrate windshields with much less attenuation than other bike horns. That is why you hear the bass-line of your neighbors music, even when they don't think they have it up too loud.

  • Auditory reaction times are known to be a little faster than visual reaction times [source].

Having a Loud Bicycle horn will get a driver’s attention and have them taking actions to keep you safe as fast as humanly possible.

Getting a driver to respond quickly is critical
Even a few seconds of time for a reacting driver is plenty to save your life. When comparing the outcomes of different pedestrian accidents, the speed of the vehicle on impact has a huge effect on the outcome of the accident. If we suppose that speed plays a similar role in bicycle accidents then if a driver going at about 30 mph (50 km/h) brakes for only a half second, your chances of survival increase from 20% to 80% (see calculation at bottom). After two seconds the car will have nearly stopped.

[dc richards 2010]

When even a split second can save your life, you need drivers to react as quickly as possible and a Loud Bicycle horn is the best way to make it happen. One of our backers said it best:
"It's all about getting people ... to snap out of their fog & stop what they're about to do." -Calvin Bean

A Loud Bicycle horn grabs a driver’s attention and gets them taking the actions to keep cyclists safe as fast as humanly possible. Help us get the horn on your bike and in the hands of cyclists worldwide by ordering a horn from

Read why traditional bike horns can't be relied on in an emergency.

Calculation footnote

Assuming that the vehicle complies with the minimum US regulated requirements for braking speeds given here as 21 ft/s^2 or 14 ft/s^2 for trucks.
So in 0.5 sec*(21 ft/s^2) in kph = 11.5 km/h. According to the graph, going from 50 km/h to 40 km/h (a difference of 10 km/h) will reduce the probability of fatality by 60% from 80% to 20%.


  1. I think this is a terrible idea. All this will do is aggravate drivers and make them more hostile to cyclists. Cyclists (like myself) hate being honked at. Now that a cyclist can honk, drivers will feel that they need to reciprocate. Have you done any studies on actual behavior on the roads with this product?

    Plus, what's to stop bike on bike honking? Do we really need a product that increases overall aggression and aggravation on the roads?

  2. In my 10 months using the horn on the roads, I have had only good experiences. Once I honked at a texting driver who was swerving into the bike lane. The guy actually rolled down window and thanked me.

    Nobody wants to hit a bike. When drivers hear my car horn they know a crash is imminent; when they brake and watch me pass by they are relieved not angry.

    We are confident that people serious enough about cycling to buy one of our horns are already more concerned about the urban environment than an average motorist. In addition, the uninterrupted path from horn to ear will be a strong motivation for our customers to honk responsibly.

    Still, I do appreciate your feedback. I strongly believe the safety benefits of the horn outweigh the concerns you raise but only time will tell.

  3. Can you discuss advantages of this over the existing and popular AirZounds horn?

    1. Hi Yokota, I've discussed that specifically in this blog post:
      Delta AirZound

      Let me know if I can help with anything else

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