Disable Backup Beeping?

[Murse-In-Airy]

Setting aside opinions for a bit, here are some empirical studies.

This is intended for anyone who may be contemplating disabling the warning sound. For those who are completely committed to this path and not turning back: this isn't directed at you.

TLDR: testing has found with high confidence that electrified/quiet vehicles are more likely to be involved in a pedestrian or cyclist accident than their ICE equivalents.

NHTSA 2009 and 2011 studies (https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/811526.pdf)

2009 study

In 2009 the National Highway Traffic Safety Administration released the report “Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles” with the finding that an HE vehicle was two times more likely to be involved in a pedestrian crash than an ICE vehicle in situations involving low-speed maneuvers (Hanna, 2009).​

2011 follow up study, applying more rigor and comparing ICE and hybrid versions of the Camry, Civic, and Accord, and the Corolla versus the Prius

Overall, the odds ratios indicate that the odds of an HE vehicle being in either a pedestrian or bicycle crash are greater than the odds of an ICE vehicle being in a similar crash with odds ratios of 1.35 and 1.57 respectively, both of which are statistically significant with p-values under 0.01 percent.​

Simulation study based on BEVs, non-NHTSA (https://www.sciencedirect.com/science/article/abs/pii/S0968090X18307472)

According to the analysis, electric vehicles have a 30% higher pedestrian traffic safety risk than internal combustion engine vehicles under high ambient sound levels. At low ambient sound levels, however, electric vehicles have only a 10% higher safety risk for pedestrians. Low levels of ambient illumination also increase the number of pedestrians involved in near-crashes for both electric vehicles and combustion engine vehicles.​

There may be other publications contradicting these or ones that are entirely inconclusive at the specified confidence levels, though I didn't see any compelling ones in my search results. For any who may be unfamiliar with hypothesis testing, the p-value mentioned in the 2011 passage represents probability that despite the numerical evidence, there is actually no difference between ICE and electrified vehicles--and in this case it was less than one hundredth of one percent.

We're not always fortunate enough to share unrestricted line of sight with bystanders or have guarantees that those bystanders won't move suddenly when assuming the coast is clear. This is probably just a slice of the increased odds mentioned in the NHTSA studies. The car is equipped to provide fair warning with no effort on your part--maybe an opportunity for someone to pause, whether instinctively or consciously, before darting into your path.

For you not to have noticed a pedestrian, cyclist, or furry friend before they shot into your path is likely defensible, at least from a moral perspective if not a legal one. But actively preventing them from hearing you is a different proposition.

So that's the risk side of the equation: higher probability of a very undesirable outcome, however unlikely it may be. It's probably mitigated to some degree by the various anti-collision measures that the car has, but if those were 100% effective, I submit we would have lots of complaints about phantom braking since the sensors would be tuned to stop if in any doubt whatsoever.

Now for the reward side of disabling or impairing the pedestrian warning system (at least in the US): removing a source of noise equivalent to an electric toothbrush or a dishwasher. The slow rolling whir is restricted to 71 dba at 30 km/h and 54 dba when stationary, and of course above 20 mph the sound is gone.

If one still considers that sound pollution, we're probably looking at a 25 foot radius at most, and only during conditions where ICE vehicles are producing no shortage of noise already. I don't have any citations for this one, though I do have a sound level meter that I may tinker with. The warning sound sure seems quieter than the under-hood fan that comes on with the A/C.

Oh good. Now we get to examine data.

Your first study, when read in detail, makes no analysis between sound and risk of accidents. It only shows that drivers of Toyota Hybrid Electric Vehicles from 2000 to 2008 were more likely to be in accidents below 35 MPH. It excludes all knowledge of what else may have been going on. More importantly to me, it excludes parking lots, the one place I think the pedestrian time may be most important. Event the paper’s own executive summery states

“While this study provides useful information about the differences in the incidence rates of HE versus ICE vehicles involved in pedestrian crashes, there are two important limitations to consider. First, the analysis of 16 States cannot be used to directly estimate the national problem size. Secondly, as indicated in an analysis of statistical power, there is not enough data to draw conclusions in all scenarios of interest such as for specific low-speed maneuvers or in parking lots.”


“While this study provides useful information about the differences in the incidence rates of HE versus ICE vehicles involved in pedestrian crashes, there are two important limitations to consider. First, the analysis of 16 States cannot be used to directly estimate the national problem size. Secondly, as indicated in an analysis of statistical power, there is not enough data to draw conclusions in all scenarios of interest such as for specific low-speed maneuvers or in parking lots.”

The authors are admitting that their paper should not be used for anything more than stating that EV’s are responsible for more accidents. No other conclusions about why are legitimate. If we’re going to base legislation on this paper, then all hybrids should be outlawed as that is the only legitimate conclusion made. You could as easily conclude that Hybrids despise humans as you can conclude lack of noise is the cause.

The authors then go on to even admit that these concerns about lack of sound are “hypothetical” concerns brought by advocacy groups. No causation has been proved. Instead congress was pressured by some lobbyists to demand sounds in EVs without any proof as to the safety of the sound or the efficacy of it as a way to prevent traffic accidents.

Your second citation is not available to me in full text but it is definitely not a randomized trial or even a historical data analysis. It is a computer model of human behavior at different noise levels. Computer models may be programmed to show whatever the author wants based on the variables entered. I have to question how many variables were programmed into the simulation, especially background noises, whether these pedestrian near-misses included a varied pedestrian behaviors, etc. But even if their simulation is perfect, unbiased, and all encompassing, I can’t take them seriously for this one assumption in the abstract:

“the high end-prices of electric vehicles indicate that electric vehicle drivers tend to have a higher prosperity index and are more likely to receive a better education, making them more alert while driving and more likely to obey traffic rules.”

On what planet are rich people better drivers and more likely to obey traffic rules? Every time I’m on the highway and get passed by someone doing 90MPH it’s a BMW, Lexus, Escalade, etc…. Every time I get cut off by someone crossing at an intersection, it’s a car I can’t afford.

No study has yet been published to show that modern electric cars, with automatic crash avoidance and emergency braking are any safer with noise versus without. There are as many people postulating the decrease in awareness from alarm fatigue as there are those postulating a benefit from more noises. One side or the other may be correct but until then laws based on hypotheticals are misplaced.

I’ll end this by saying my dog runs out to bark at my car every time I get home. He forces my car to automatically brake all the time. I couldn’t hit him if I wanted to. Not true in my F150. So my silent car is safer than my (still very quiet) F150.

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[satchel prefect]

Oh good. Now we get to examine data.

Your first study, when read in detail, makes no analysis between sound and risk of accidents. It only shows that drivers of Toyota Hybrid Electric Vehicles from 2000 to 2008 were more likely to be in accidents below 35 MPH. It excludes all knowledge of what else may have been going on. More importantly to me, it excludes parking lots, the one place I think the pedestrian time may be most important. Event the paper’s own executive summery states

“While this study provides useful information about the differences in the incidence rates of HE versus ICE vehicles involved in pedestrian crashes, there are two important limitations to consider. First, the analysis of 16 States cannot be used to directly estimate the national problem size. Secondly, as indicated in an analysis of statistical power, there is not enough data to draw conclusions in all scenarios of interest such as for specific low-speed maneuvers or in parking lots.”


“While this study provides useful information about the differences in the incidence rates of HE versus ICE vehicles involved in pedestrian crashes, there are two important limitations to consider. First, the analysis of 16 States cannot be used to directly estimate the national problem size. Secondly, as indicated in an analysis of statistical power, there is not enough data to draw conclusions in all scenarios of interest such as for specific low-speed maneuvers or in parking lots.”

The study is not infallible, and like any other statistical inference, caveat emptor. Examining the effect of the noise as an isolated treatment is probably unrealistic in an uncontrolled environment with a combined sample size of over 1,000,000 vehicles. Comparing ICE and hybrid versions of the same vehicles appears to be the approach they applied. Some will find that reasonable, and some will not.

The other side of the coin regarding insufficient data to draw conclusions on some scenarios is that they were hoping to make more granular observations than "low speed maneuvers," but with accidents already being infrequent occurrences, there weren't enough occurrences in the more specific buckets they defined. They also could have attempted to look at age, size, and athleticism of the pedestrians but wouldn't have had sufficient data to support that either. It may seem like they are cutting corners by lumping low speed maneuvers into a single aggregate, but that is more responsible than making claims the data could not support, especially if they call themselves out.

You could as easily conclude that Hybrids despise humans as you can conclude lack of noise is the cause.

Not sure I follow this unless I am misreading it. Are you referring to the drivers or the cars themselves?

Your second citation is not available to me in full text but it is definitely not a randomized trial or even a historical data analysis. It is a computer model of human behavior at different noise levels. Computer models may be programmed to show whatever the author wants based on the variables entered. I have to question how many variables were programmed into the simulation, especially background noises, whether these pedestrian near-misses included a varied pedestrian behaviors, etc. But even if their simulation is perfect, unbiased, and all encompassing, I can’t take them seriously for this one assumption in the abstract:

Yes, and I did cite this as a simulation in the hope that it would be considered and digested as such. What you have outlined is helpful for anyone reading simulation results. It's also important to question the more speculative thing like the simulation recognize confirmation bias before falling into it. I see how this can be the edge of it. Thank you for keeping us in check. Caveat emptor.

“the high end-prices of electric vehicles indicate that electric vehicle drivers tend to have a higher prosperity index and are more likely to receive a better education, making them more alert while driving and more likely to obey traffic rules.”

On what planet are rich people better drivers and more likely to obey traffic rules? Every time I’m on the highway and get passed by someone doing 90MPH it’s a BMW, Lexus, Escalade, etc…. Every time I get cut off by someone crossing at an intersection, it’s a car I can’t afford.

On this I agree with you and disagree with the article as well.

No study has yet been published to show that modern electric cars, with automatic crash avoidance and emergency braking are any safer with noise versus without. There are as many people postulating the decrease in awareness from alarm fatigue as there are those postulating a benefit from more noises. One side or the other may be correct but until then laws based on hypotheticals are misplaced.

I’ll end this by saying my dog runs out to bark at my car every time I get home. He forces my car to automatically brake all the time. I couldn’t hit him if I wanted to. Not true in my F150. So my silent car is safer than my (still very quiet) F150.

Yes the world has moved on and there are many questions around the effectiveness of the multifaceted safety measures we see today. In the absence of data, it's natural to speculate, and up to the actor to decide whether aging quantitative inferential studies are worth considering in the pursuit of altering an existing product to make less noise than a dishwasher or microwave.

 

[Murse-In-Airy]

The study is not infallible, and like any other statistical inference, caveat emptor. Examining the effect of the noise as an isolated treatment is probably unrealistic in an uncontrolled environment with a combined sample size of over 1,000,000 vehicles. Comparing ICE and hybrid versions of the same vehicles appears to be the approach they applied. Some will find that reasonable, and some will not.

The other side of the coin regarding insufficient data to draw conclusions on some scenarios is that they were hoping to make more granular observations than "low speed maneuvers," but with accidents already being infrequent occurrences, there weren't enough occurrences in the more specific buckets they defined. They also could have attempted to look at age, size, and athleticism of the pedestrians but wouldn't have had sufficient data to support that either. It may seem like they are cutting corners by lumping low speed maneuvers into a single aggregate, but that is more responsible than making claims the data could not support, especially if they call themselves out.




Not sure I follow this unless I am misreading it. Are you referring to the drivers or the cars themselves?



Yes, and I did cite this as a simulation in the hope that it would be considered and digested as such. What you have outlined is helpful for anyone reading simulation results. It's also important to question the more speculative thing like the simulation recognize confirmation bias before falling into it. I see how this can be the edge of it. Thank you for keeping us in check. Caveat emptor.



On this I agree with you and disagree with the article as well.



Yes the world has moved on and there are many questions around the effectiveness of the multifaceted safety measures we see today. In the absence of data, it's natural to speculate, and up to the actor to decide whether aging quantitative inferential studies are worth considering in the pursuit of altering an existing product to make less noise than a dishwasher or microwave.

Excellent discussion. I thank you so much.
As far as Hybrids hating humans… a bit of hyperbole to emphasize that the only viable conclusion from this research is that hybrids hit people more than ice vehicles. If we wish to infer that is due to them being quiet, then perhaps we can alap infer nefarious purposes of the cars themselves. It is just as plausible. ?

 

[mkhuffman]

Good discussion but why post articles that cannot be used to draw any conclusions about how much safer fake noises are as proof fake noises are needed? It is basically propaganda the politicians are using as justification to force us to do what they want us to do.

I am going to go back to enjoying my silent car now, which is just as safe as the ICE Accord with it's mufflers and sound deadening material.

 

[CarGuy11]

Isn't the low speed noise regulation the same for going forward & reverse? So why does Ford add beeping in reverse?

 

[Murse-In-Airy]

Isn't the low speed noise regulation the same for going forward & reverse? So why does Ford add beeping in reverse?

That’s what I said! ?
If the vehicle emitted the same low hum going backwards, this thread wouldn’t even exist… for the good of all.

 

[Kamuelaflyer]

Isn't the low speed noise regulation the same for going forward & reverse? So why does Ford add beeping in reverse?

That’s what I said! ?
If the vehicle emitted the same low hum going backwards, this thread wouldn’t even exist… for the good of all.

Somewhat tangential but ...

The various lobbying and advocacy groups for the visually impaired are trying to force a standard sound for low-speed EV driving (the hum below roughly 20 mph in the MME) and for backing up. With each manufacturer picking their own sounds, it can be a bit to process for the visually handicapped apparently. They also like the beep in reverse because everyone knows what it means. The issue is, of course, getting the masses to respect the sound and not be dumbasses and stand behind cars making it.

If they're going to standardize a low-speed forward sound I'm going to have to insist upon it being the jetson's car sound. Carry on.

 

[Jimrpa]

Somewhat tangential but ...

The various lobbying and advocacy groups for the visually impaired are trying to force a standard sound for low-speed EV driving (the hum below roughly 20 mph in the MME) and for backing up. With each manufacturer picking their own sounds, it can be a bit to process for the visually handicapped apparently. They also like the beep in reverse because everyone knows what it means. The issue is, of course, getting the masses to respect the sound and not be dumbasses and stand behind cars making it.

If they're going to standardize a low-speed forward sound I'm going to have to insist upon it being the jetson's car sound. Carry on.

I want the transition from from low-speed to high-speed sound to be the sound the Orville makes when it engages its quantum drive ?

 

[Murse-In-Airy]

I support the Jetsons sound AND the quantum drive sound. It’s the dump truck sound I can’t get behind. (But maybe that was the intent).

 

[Kamuelaflyer]

It’s the dump truck sound I can’t get behind. (But maybe that was the intent).

? ? ?

 

[azerik]

I did the 'old rag stuffed under it' test. It's muffled a bit, probably enough I'll stick with this. That said. once I did that I found myself driving around wondering where the sound went and doing it myself in my head. FFS. Turn it off! lol. wawawawawawawa. 15mph was loud enough i had to explain to my it was the sounds of the MME, not the Tesla we were behind. The backup sound is muffled enough I'm probably ok with it as it'll come in handy in Ikea parking lots. If I went o Ikea with my EV Focus no one knew I was behind them. Drove me nuts with a family gingerly wandering down the parking isle blocking the whole thing, randomly stopping to show each other videos. If I'd pump the brakes on that car the vacuum pump would kick in with a "FFFTTTTPTPPPPPTTTTFFFFTTTPPPP" And people would jump and move.

 

[Murse-In-Airy]

Ok folks. I think I finally figured out why this thread was started, why I have such extreme hate of the industrial backup beep. The airport where I spend way too many nights, occasionally trying to sleep, starts plowing snow with a large front end loader, 5 feet from my “work bedroom” AT 4AM!!!

I had a very busy shift Friday. Went to sleep at 1AM hoping to sleep until 5AM. Then at 4AM on the dot…BEEP BEEP BEEP BEEP.
All I wanted was one more hour of sleep. Instead I think I need inpatient treatment now

On a different note, my rental car today is a Kia Nero Plug-In Hybrid with a very pleasant backup chime. It also has way better instrument cluster and infotainment setup with useful information.

 

[Reality Check]

I didn't measure it myself. Just went by what was mentioned earlier in this thread (4.8) and that a 4.7 ohm/5 watt resistor worked. My local electronics store didn't have a 4.7 ohm, so I tried 3.6 ohm 10 watt which triggered the warning on the dash and 5.1 ohm 10 watt which is working as expected.

Weird, so the 3.6 ohm must’ve triggered a warning for being too high of a load, while the lower 5.1 ohm load was acceptable.

It seems the ideal would be to find the lowest acceptable load (i.e. highest ohm) resistor, and that way it would use & dissipate the least heat (i.e. watts) and could therefore be smaller.

10 watts seems like a lot of audio power for a relatively high-pitched (bass free) synthesized backup warning tone, so seems like a much higher load & power resistor than should be needed to fake the MME into thinking it’s the little stock speaker!

The wires to the speaker look pretty thin, so I’m guessing a much higher ohm resistor should work even better!

(Clearly an open circuit is the lowest load possible, and so since that *also* triggers a dashboard warning … the MME must be checking for a wide range between a high-ohm minimum *and* low-ohm maximum load.)

 

[Reality Check]

I made what I like to call the 'beeper deleter'. No, it's not for sale since technically it is illegal to defeat this, but if you're interested in making your own I can give you some simple info via PM.

I simply found the mating connector and stuck a 5w resistor in there then sealed it up with adhesive heat shrink and some electrical tape for good measure. I haven't installed it yet but it should work just fine.

Now that’s really slick! What is the connector name/type and size … and where are they sold? I’d like to do the same!!

 

[mkhuffman]

Now that’s really slick! What is the connector name/type and size … and where are they sold? I’d like to do the same!!

Somewhere in these 23 pages the parts are specified. If you can't find them, let me know and I will see if I can find them for you. And I think there is link to the site that makes something like this and sells them.

I used the info in this thread to make a volume control for my car. It is always turned down, so really the deleter would have been fine, but I can turn up the annoying noise if for some stupid reason I want to.

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