26 ms·

City noise pollution is a factor in all-cause mortality due to long-term, barely perceptible stress effects on the cardiovascular system. Unfortunately, one of

City noise pollution is a factor in all-cause mortality due to long-term, barely perceptible stress effects on the cardiovascular system. Unfortunately, one of the most disturbing and frequency sources of city noise pollution is from emergency vehicle sirens. I gave a presentation at the Audio Engineering Society titled "Iatrogenic Sound", on the tragic irony of how sirens may causally contribute to the heart attacks and strokes that ambulances are rushing to treat. We were exploring the acoustics of urban design and the sound-design of sirens. The sweeping "wailer" siren is in fact one of the worst possible designs imaginable - all the wrong characteristics for locatability of source, annoyance versus attention ratio, penetration of dwellings etc. Add to that the design of modern "luxury" cars which are soundproofed, fitted with anti-noise and blaring ICE systems to block the world out. There isn't an easy solution. Most laws give police, fire and ambulance crews "discretion" in the use of sirens. In the UK that's Article 99. But here, the removal of crown immunity and insurance pressures mean the crew now always deploy, even at times of night when it would have previously been illegal under other laws. I expect the same complex spheres of interest clash in NYC too.

FredPret 4y ago
I used to live next to a high school. Every Saturday, starting at 8am, they would have an athletics meet. Whistles, starting guns, announcements over megaphone. I wish that was illegal
Gracana 4y ago
That's fascinating. What would a good emergency vehicle siren sound like?
- ARandomerDude 4y ago
  Whoooooeeeeew, whoooooeeeeew, whoew, whoew, whoew, whoew.
  - herodoturtle 4y ago
    I know it goes against the spirit of HN etiquette, but damn this comment was funny ^_^
- dazc 4y ago
  It already exists in the form of silent flashing blue lights. Anyone who hasn't already seen these lights approaching will usually panic when they suddenly hear a loud siren and become more of an obstacle than if they just carried on moving forward as normal. I see this scenario played out every weekend when I visit a friend who lives near a busy intersection of two major routes. Emergency vehicles impede their own progress nearly every time by deploying sirens.
- ars 4y ago
  It would sound more like broad-band static. That kind of sound is much easier to localize, so it doesn't have to be as loud. They would need to mix in a bit of siren sound so you can distinguish it from a backup alert.
  - ajb 4y ago
    What's odd is that 15-20 years ago they were trying out adding white noise to sirens, they still had the recognisable sound but also a blast of static noise. It would be interesting to know why they didn't follow through.
  - HPsquared 4y ago
    Also it doesn't focus all its energy on a narrow range of cilia in the inner ear. Like the difference between a small, intense light in your eyes vs. a larger, less intense light.
- endymi0n 4y ago
  Here in Germany, I'm seeing more and more emergency vehicles having their siren off by default in low to medium traffic situations (even in a large city like Berlin) and only activating it when they enter dangerous situations (like large crossings or passing red lights) or need space. I don't know whether that's current regulation already, but I think it's a rather nice gesture and definitely reduces the noise background ever so slightly.
  - mathieuh 4y ago
    In Northern Ireland where I am ambulances only seem to turn their sirens on when approaching junctions where they will have to go through a red light, otherwise they just have their lights on
    - Ntrails 4y ago
      They'll also blip them when traffic isn't getting out of the way, but that also seems incredibly reasonable. I honestly can't remember the last time I saw a "needless" siren on an emergency vehicle. But, like you, I am in the UK and the rules are different here
  - xen0 4y ago
    In Munich, they seem to regard every crossing as dangerous. :( It really is quite obnoxious.
    - hnbad 4y ago
      In Germany police and emergency vehicles are only allowed to use "Sonderrechte" (special privileges) when using both the lights and the sirens. So if they want to pass a red light or go the wrong way in a one way lane they have to use the sirens. Note that this is not technically a legal requirement as the law grants them a general exemption but the administrative regulations make this mandatory. That said, I have seen police cars go the wrong way using hazard lights instead of the blue lights (and no sirens) so I'm not sure what the actual consequences for not following these regulations are.
  - 4y ago
- nonrandomstring 4y ago
  Good qualities we identified in a discussion: - directional - many short duration rather than continuous - sonorous (melodic or consonant) - amplitude appropriate to time of day and danger A big mistake we make is confusing "attention", "arresting" and "annoying" qualities. Dissonant sounds seem like they grab your "attention" quicker, but that's not necessarily true, it's really about the spectrum morphology in the first 100ms - those sounds (like bells) have better localisation qualities - they tend to elicit an orientation response and have better front-rear ambiguity so we can position them better. Knowing where an emergency vehicle is, is as important as just knowing it's there. From video evidence of interchanges and roundabouts what we see is that the sound of sustained sweep sirens often creates chaos, with drivers panicking, pulling on to pavements or making other rash and dangerous sudden manoeuvres.
- wongarsu 4y ago
  There is the "European" siren (Martinshorn in German) which is just two tones (typically a' followed by d'') and sounds like [1]. There is also a slightly higher pitched version used by vehicles stationed inside cities. It's still loud, but subjectively less stress inducing and objectively easier to locate. The most obvious feature is that you can very easily tell if the emergency vehicle is moving towards you or away from you as well as the approximate relative speed because the doppler shift is really easy to pick up by ear. 1: https://freesound.org/people/DominikBraun/sounds/459880/ https://freesound.org/people/DominikBraun/sounds/459880/
test1235 4y ago
>blaring ICE systems Internal combustion engine?
- trainsarebetter 4y ago
  Exactly
- esses 4y ago
  In Car Entertainment
ghostly_s 4y ago
> City noise pollution is a factor in all-cause mortality due to long-term, barely perceptible stress effects on the cardiovascular system. Source? would appreciate some ammo to advocate for this locally.
- nonrandomstring 4y ago
  I don't have access to my old slide deck atm, but pretty sure a a major WHO report full of links came out the past year or so. See where this leads you [1]. [1] https://www.euro.who.int/en/health-topics/environment-and-health/noise https://www.euro.who.int/en/health-topics/environment-and-he...
paganel 4y ago
> all the wrong characteristics for locatability of source Glad I'm not the only one who has noticed this, I thought I was going crazy because in the majority of cases when I'm behind the wheel and I start hearing an ambulance siren I can't honestly tell from where it is coming from. I'm kind of aware of the general area, like it's coming from that general part, or that other general part, but I'm never sure until I actually can see the ambulance itself.
mattmanser 4y ago
You've obviously studied this, but having actually lived in a city center police sirens are actually fairly rare. Despite what you say they rarely sound them at night unless they really have a need, at least in Nottingham. Much worse for causing often unexpected and very grating noise were: 1. Bin men, especially now they collect glass 2. Diesel black cabs having to put their foot down to get up a hill 3. Taxis idling outside your window waiting for a pickup or just waiting for their next dispatch on double yellows in middle of night 4. Scaffolding being put up or taken down. Incredibly noisy, actually has to be done fairly regularly, many companies illegally do this at the weekend in the early morning as it's a part time job for them 5. Skateboarders, one of the most anti-social hobbies for everyone else around them [1] I lived on a bit of a hill, which caused 2 and attracted 5. Since moving to a village again my sleep quality improved overnight. I didn't realize quite how badly it was affecting me. [1] As it seems to be causing confusion, the anti-social behaviour is against non-skateboarders "Environmental antisocial behaviour is when a person’s actions affect the wider environment, such as public spaces or buildings." https://www.met.police.uk/advice/advice-and-information/asb/asb/antisocial-behaviour/what-is-antisocial-behaviour/ https://www.met.police.uk/advice/advice-and-information/asb/...
- deleted 4y ago
  [deleted]
- diordiderot 4y ago
  6. Mopeds
- chronogram 4y ago
  The only Nottingham I know is in the UK, and the UK is specifically mentioned by GP.
- NeutralForest 4y ago
  Depends on the city, I'm not far from a hospital as well as a police station and the noise it generates is intense. The ambulances more so than the police. Bikes (mostly mopeds) are really really annoying as well, some of them, I don't know why or how generate insane amounts of noise. Agreed on the scaffolding and overall works, I blame the random urban planning.
jstummbillig 4y ago
Can you show your data? While noise pollution is self-evidently unpleasant, not providing numbers when claiming a connection between heart disease to, well, anything at all, seems a bit... lax.
- nonrandomstring 4y ago
  If you're interested in this you need to search under the terms: psychoacoustics of subjective loudness perception, annoyance, sound and attention, arresting sound, sound localisation/directivity or spatial audio in exterior acoustics. These will give you a measure of the breadth of this research field. For health effects you can start with the WHO or IOA (institute of acoustics) searching under cardiovascular effects of long term exposure, accumulative harms or exposure, and noise harm metrics respectively.
jasfi 4y ago
You can do something about stress: Ashwagandha reduces cortisol levels. This is not an ideal solution, you should still do something to fix/remove the stressor, but it's better than nothing for sure.
- jen729w 4y ago
  Source please. This is an unsubstantiated medical claim. (Partner is a medical writer. Don't make claims that you can't back up!)
  - jasfi 4y ago
    https://journals.sagepub.com/doi/pdf/10.4103/0253-7176.106022 https://journals.sagepub.com/doi/pdf/10.4103/0253-7176.10602... Note: don't take it every day.
deleted 4y ago
[deleted]
toxik 4y ago
Far and away the most reoccurring noise for us is airplanes landing at Bromma Airport in Stockholm, Sweden. Because half of the city is in the descent path, we get low flying commercial airplanes, sometimes a dozen an hour. Incredible how it’s even remotely legal. Especially since most plebs only go to Arlanda Airport, which is an hour away by car. Politicians and businessmen use Bromma. Second loudest noise is heavy traffic, like trucks. They always seem to be speeding in low speed areas too. I only noticed because my daughter would wake up because of them.
- piva00 4y ago
  I live in Stockholm and I'm originally from São Paulo, Brazil. Bromma is quite annoying (even more when I lived around Sundbyberg) but is still relatively tame compared to Congonhas airport in São Paulo. Either way I can't believe that both airports are still allowed to operate, I lived under both on/off-ramps and even though your mind learns to filter out the noise there's something you can still feel under your skin every time a plane buzzes by...
  - easytiger 4y ago
    > Either way I can't believe that both airports are still allowed to operate, I lived under both on/off-ramps 1. Bromma Stockholm Airport Opened 23 May 1936 2. São Paulo/Congonhas–Deputado Freitas Nobre Airport - Opened 12 April 1936 Interestingly both opened 86 years ago. When did you move to near the area of their operation? Most airports are built away from conurbations which then grow around them, in my observation
    - piva00 4y ago
      In São Paulo I lived close to Congonhas from around 2006-2015. And I lived around Bromma airport in 2017-2018. The issue with Congonhas is exactly that the city grew towards it after Brazil started to urbanise in the 50s, what I cannot believe is that even after Guarulhos was expanded there was some talks about shutting down Congonhas that never materialised, even though it would be a massive improvement for the city both regarding noise and land-use...
easytiger 4y ago
UK ambulance and fire sirens are designed for wide open low rise towns. In 40ft wide streets with tall buildings it is physically painful let alone subconsciously stressful.
- nonrandomstring 4y ago
  Yes, sometimes, if trapped between two parallel walls where an emergency vehicle passes, the loudness can be doubled (+6dB SPL) as the reflected waves meet in-phase. This crosses the level causing hearing damage. But because the vehicle is moving we currently dodge classifying this as harm/assault by counting it as a transient rather than sustained exposure.
  - easytiger 4y ago
    Interesting. I live in central London and moved flat a few years ago. Only noise issues i had were motorcycles with modified exhausts and emergency sirens. It's really quite confusing why they are considered necessary. New flat is high up and has 3 inch thick windows so we can't hear a thing unless its really nearby. But i have the door open sometimes and you can hear what sounds like a massive terrorist response of emergency sirens. THe you look over and see its one ambulance traversing traffic in an area with many angled buildings. I recall years ago there was a plan to move them to white noise based systems. What happened with that
- vultour 4y ago
  I'm not sure if there is any substantiated benefit to the extreme volume of the UK ambulance sirens. Coming from a country that also has many wide open low rise towns I've never heard any complaints about the volume of our emergency vehicles.
  - easytiger 4y ago
    France by any chance? Their sirens are much less painful in the similarly shaped streets with 8/9 story buildings
ricardonunez 4y ago
Does getting used to the noise still affect people on a subconscious level? A family member has a newly built fire department and it used to alert me every time I heard the siren, but now I rarely notice. I was curious how that affects people living there in the long term.
reledi 4y ago
Central London here. Use of siren is very well controlled in my opinion, especially compared to other countries and cities. I find they're used for short periods such as when approaching an intersection. What's the most disturbing for us are people on on scooters, motorbikes, or cars with modified mufflers or engines and excessive revving. Much more frequent, and they love cruising at all hours of the night.
- avianlyric 4y ago
  Yeah it’s obvious emergency crews in London have been given some very stringent training on the use of sirens. Only used for a short period on approach to junctions, turned off if it’s clear that traffic can’t create space for them (so they don’t just sit in traffic wailing away), alternating the siren tone after passing each junction so it’s clear to others you need to pay attention again as the vehicle has cleared an obstacle and is going to start accelerating. They do an extremely good job of making sure that people know they’re there, without being unnecessarily obnoxious.
kiliantics 4y ago
> Add to that the design of modern "luxury" cars which are soundproofed, fitted with anti-noise and blaring ICE systems to block the world out. The more I learn and think about this, the more it just seems absolutely insane to me how much we have given up for cars. Every horn and siren has to get louder, because the drivers have to hear them. No concern for others though, we must always appease the drivers first. Why can't we remove sound insulation in cars as a matter of policy? It would fix so many issues. Obviously removing most cars from cities would be a step better. In NYC, police and fire fighters are usually the stereotypical Jabronis who themselves drive the muscle cars and trucks to get to work (and park on the sidewalk outside the precinct). So of course they don't care about the noise they are pumping out on their sirens either. I live near a fire station in Brooklyn and it's truly deafening, even in the middle of the night when there's no traffic.
- zip1234 4y ago
  I'm pretty sure the sirens are just as loud as they are because the people in the completely sound insulated vehicles can't hear them otherwise.
dayvid 4y ago
Definitely this. As someone born in NYC who moved away as a teen and later moved back after a year, the NYC sirens are insanely louder compared to other city sirens. I'm not sure if it's due to the density of buildings, but I think they just set the volume louder. It's incredibly annoying, affects far more people than necessary and could be handled better.
- ericbarrett 4y ago
  You can always see multiple people plugging their ears when an ambulance goes down a busy street in NYC—it's a painful and resonant buzz in your skull if you don't. The sirens must be well past the level that causes damage.
klyrs 4y ago
I think there is a relatively easy solution, but it's hard to roll out today. Just as cell phones interruptively broadcast Amber Alerts, car radios should interruptively broadcast emergency vehicle sirens. There should still be an audible siren for pedestrians, but it could be much quieter. The trick is keeping the broadcast tight, without giving governments the ability to passively track the movements of all vehicles.
standardUser 4y ago
Having lived in city centers my entire life, if you had asked me to write a top 10 list of worst noise pollution sources, sirens wouldn't even make the list.

FredPret 4y ago

I used to live next to a high school. Every Saturday, starting at 8am, they would have an athletics meet. Whistles, starting guns, announcements over megaphone. I wish that was illegal

Gracana 4y ago

That's fascinating. What would a good emergency vehicle siren sound like?

ARandomerDude 4y ago
Whoooooeeeeew, whoooooeeeeew, whoew, whoew, whoew, whoew.
- herodoturtle 4y ago
  I know it goes against the spirit of HN etiquette, but damn this comment was funny ^_^
dazc 4y ago
It already exists in the form of silent flashing blue lights. Anyone who hasn't already seen these lights approaching will usually panic when they suddenly hear a loud siren and become more of an obstacle than if they just carried on moving forward as normal. I see this scenario played out every weekend when I visit a friend who lives near a busy intersection of two major routes. Emergency vehicles impede their own progress nearly every time by deploying sirens.
ars 4y ago
It would sound more like broad-band static. That kind of sound is much easier to localize, so it doesn't have to be as loud. They would need to mix in a bit of siren sound so you can distinguish it from a backup alert.
- ajb 4y ago
  What's odd is that 15-20 years ago they were trying out adding white noise to sirens, they still had the recognisable sound but also a blast of static noise. It would be interesting to know why they didn't follow through.
- HPsquared 4y ago
  Also it doesn't focus all its energy on a narrow range of cilia in the inner ear. Like the difference between a small, intense light in your eyes vs. a larger, less intense light.
endymi0n 4y ago
Here in Germany, I'm seeing more and more emergency vehicles having their siren off by default in low to medium traffic situations (even in a large city like Berlin) and only activating it when they enter dangerous situations (like large crossings or passing red lights) or need space. I don't know whether that's current regulation already, but I think it's a rather nice gesture and definitely reduces the noise background ever so slightly.
- mathieuh 4y ago
  In Northern Ireland where I am ambulances only seem to turn their sirens on when approaching junctions where they will have to go through a red light, otherwise they just have their lights on
  - Ntrails 4y ago
    They'll also blip them when traffic isn't getting out of the way, but that also seems incredibly reasonable. I honestly can't remember the last time I saw a "needless" siren on an emergency vehicle. But, like you, I am in the UK and the rules are different here
- xen0 4y ago
  In Munich, they seem to regard every crossing as dangerous. :( It really is quite obnoxious.
  - hnbad 4y ago
    In Germany police and emergency vehicles are only allowed to use "Sonderrechte" (special privileges) when using both the lights and the sirens. So if they want to pass a red light or go the wrong way in a one way lane they have to use the sirens. Note that this is not technically a legal requirement as the law grants them a general exemption but the administrative regulations make this mandatory. That said, I have seen police cars go the wrong way using hazard lights instead of the blue lights (and no sirens) so I'm not sure what the actual consequences for not following these regulations are.
- 4y ago
nonrandomstring 4y ago
Good qualities we identified in a discussion: - directional - many short duration rather than continuous - sonorous (melodic or consonant) - amplitude appropriate to time of day and danger A big mistake we make is confusing "attention", "arresting" and "annoying" qualities. Dissonant sounds seem like they grab your "attention" quicker, but that's not necessarily true, it's really about the spectrum morphology in the first 100ms - those sounds (like bells) have better localisation qualities - they tend to elicit an orientation response and have better front-rear ambiguity so we can position them better. Knowing where an emergency vehicle is, is as important as just knowing it's there. From video evidence of interchanges and roundabouts what we see is that the sound of sustained sweep sirens often creates chaos, with drivers panicking, pulling on to pavements or making other rash and dangerous sudden manoeuvres.
wongarsu 4y ago
There is the "European" siren (Martinshorn in German) which is just two tones (typically a' followed by d'') and sounds like [1]. There is also a slightly higher pitched version used by vehicles stationed inside cities. It's still loud, but subjectively less stress inducing and objectively easier to locate. The most obvious feature is that you can very easily tell if the emergency vehicle is moving towards you or away from you as well as the approximate relative speed because the doppler shift is really easy to pick up by ear. 1: https://freesound.org/people/DominikBraun/sounds/459880/ https://freesound.org/people/DominikBraun/sounds/459880/

test1235 4y ago

>blaring ICE systems Internal combustion engine?

trainsarebetter 4y ago
Exactly
esses 4y ago
In Car Entertainment

ghostly_s 4y ago

> City noise pollution is a factor in all-cause mortality due to long-term, barely perceptible stress effects on the cardiovascular system. Source? would appreciate some ammo to advocate for this locally.

nonrandomstring 4y ago
I don't have access to my old slide deck atm, but pretty sure a a major WHO report full of links came out the past year or so. See where this leads you [1]. [1] https://www.euro.who.int/en/health-topics/environment-and-health/noise https://www.euro.who.int/en/health-topics/environment-and-he...

paganel 4y ago

> all the wrong characteristics for locatability of source Glad I'm not the only one who has noticed this, I thought I was going crazy because in the majority of cases when I'm behind the wheel and I start hearing an ambulance siren I can't honestly tell from where it is coming from. I'm kind of aware of the general area, like it's coming from that general part, or that other general part, but I'm never sure until I actually can see the ambulance itself.

mattmanser 4y ago

You've obviously studied this, but having actually lived in a city center police sirens are actually fairly rare. Despite what you say they rarely sound them at night unless they really have a need, at least in Nottingham. Much worse for causing often unexpected and very grating noise were: 1. Bin men, especially now they collect glass 2. Diesel black cabs having to put their foot down to get up a hill 3. Taxis idling outside your window waiting for a pickup or just waiting for their next dispatch on double yellows in middle of night 4. Scaffolding being put up or taken down. Incredibly noisy, actually has to be done fairly regularly, many companies illegally do this at the weekend in the early morning as it's a part time job for them 5. Skateboarders, one of the most anti-social hobbies for everyone else around them [1] I lived on a bit of a hill, which caused 2 and attracted 5. Since moving to a village again my sleep quality improved overnight. I didn't realize quite how badly it was affecting me. [1] As it seems to be causing confusion, the anti-social behaviour is against non-skateboarders "Environmental antisocial behaviour is when a person’s actions affect the wider environment, such as public spaces or buildings." https://www.met.police.uk/advice/advice-and-information/asb/asb/antisocial-behaviour/what-is-antisocial-behaviour/ https://www.met.police.uk/advice/advice-and-information/asb/...

deleted 4y ago
[deleted]
diordiderot 4y ago
6. Mopeds
chronogram 4y ago
The only Nottingham I know is in the UK, and the UK is specifically mentioned by GP.
NeutralForest 4y ago
Depends on the city, I'm not far from a hospital as well as a police station and the noise it generates is intense. The ambulances more so than the police. Bikes (mostly mopeds) are really really annoying as well, some of them, I don't know why or how generate insane amounts of noise. Agreed on the scaffolding and overall works, I blame the random urban planning.

jstummbillig 4y ago

Can you show your data? While noise pollution is self-evidently unpleasant, not providing numbers when claiming a connection between heart disease to, well, anything at all, seems a bit... lax.

nonrandomstring 4y ago
If you're interested in this you need to search under the terms: psychoacoustics of subjective loudness perception, annoyance, sound and attention, arresting sound, sound localisation/directivity or spatial audio in exterior acoustics. These will give you a measure of the breadth of this research field. For health effects you can start with the WHO or IOA (institute of acoustics) searching under cardiovascular effects of long term exposure, accumulative harms or exposure, and noise harm metrics respectively.

jasfi 4y ago

You can do something about stress: Ashwagandha reduces cortisol levels. This is not an ideal solution, you should still do something to fix/remove the stressor, but it's better than nothing for sure.

jen729w 4y ago
Source please. This is an unsubstantiated medical claim. (Partner is a medical writer. Don't make claims that you can't back up!)
- jasfi 4y ago
  https://journals.sagepub.com/doi/pdf/10.4103/0253-7176.106022 https://journals.sagepub.com/doi/pdf/10.4103/0253-7176.10602... Note: don't take it every day.

deleted 4y ago

[deleted]

toxik 4y ago

Far and away the most reoccurring noise for us is airplanes landing at Bromma Airport in Stockholm, Sweden. Because half of the city is in the descent path, we get low flying commercial airplanes, sometimes a dozen an hour. Incredible how it’s even remotely legal. Especially since most plebs only go to Arlanda Airport, which is an hour away by car. Politicians and businessmen use Bromma. Second loudest noise is heavy traffic, like trucks. They always seem to be speeding in low speed areas too. I only noticed because my daughter would wake up because of them.

piva00 4y ago
I live in Stockholm and I'm originally from São Paulo, Brazil. Bromma is quite annoying (even more when I lived around Sundbyberg) but is still relatively tame compared to Congonhas airport in São Paulo. Either way I can't believe that both airports are still allowed to operate, I lived under both on/off-ramps and even though your mind learns to filter out the noise there's something you can still feel under your skin every time a plane buzzes by...
- easytiger 4y ago
  > Either way I can't believe that both airports are still allowed to operate, I lived under both on/off-ramps 1. Bromma Stockholm Airport Opened 23 May 1936 2. São Paulo/Congonhas–Deputado Freitas Nobre Airport - Opened 12 April 1936 Interestingly both opened 86 years ago. When did you move to near the area of their operation? Most airports are built away from conurbations which then grow around them, in my observation
  - piva00 4y ago
    In São Paulo I lived close to Congonhas from around 2006-2015. And I lived around Bromma airport in 2017-2018. The issue with Congonhas is exactly that the city grew towards it after Brazil started to urbanise in the 50s, what I cannot believe is that even after Guarulhos was expanded there was some talks about shutting down Congonhas that never materialised, even though it would be a massive improvement for the city both regarding noise and land-use...

easytiger 4y ago

UK ambulance and fire sirens are designed for wide open low rise towns. In 40ft wide streets with tall buildings it is physically painful let alone subconsciously stressful.

nonrandomstring 4y ago
Yes, sometimes, if trapped between two parallel walls where an emergency vehicle passes, the loudness can be doubled (+6dB SPL) as the reflected waves meet in-phase. This crosses the level causing hearing damage. But because the vehicle is moving we currently dodge classifying this as harm/assault by counting it as a transient rather than sustained exposure.
- easytiger 4y ago
  Interesting. I live in central London and moved flat a few years ago. Only noise issues i had were motorcycles with modified exhausts and emergency sirens. It's really quite confusing why they are considered necessary. New flat is high up and has 3 inch thick windows so we can't hear a thing unless its really nearby. But i have the door open sometimes and you can hear what sounds like a massive terrorist response of emergency sirens. THe you look over and see its one ambulance traversing traffic in an area with many angled buildings. I recall years ago there was a plan to move them to white noise based systems. What happened with that
vultour 4y ago
I'm not sure if there is any substantiated benefit to the extreme volume of the UK ambulance sirens. Coming from a country that also has many wide open low rise towns I've never heard any complaints about the volume of our emergency vehicles.
- easytiger 4y ago
  France by any chance? Their sirens are much less painful in the similarly shaped streets with 8/9 story buildings

ricardonunez 4y ago

Does getting used to the noise still affect people on a subconscious level? A family member has a newly built fire department and it used to alert me every time I heard the siren, but now I rarely notice. I was curious how that affects people living there in the long term.

reledi 4y ago

Central London here. Use of siren is very well controlled in my opinion, especially compared to other countries and cities. I find they're used for short periods such as when approaching an intersection. What's the most disturbing for us are people on on scooters, motorbikes, or cars with modified mufflers or engines and excessive revving. Much more frequent, and they love cruising at all hours of the night.

avianlyric 4y ago
Yeah it’s obvious emergency crews in London have been given some very stringent training on the use of sirens. Only used for a short period on approach to junctions, turned off if it’s clear that traffic can’t create space for them (so they don’t just sit in traffic wailing away), alternating the siren tone after passing each junction so it’s clear to others you need to pay attention again as the vehicle has cleared an obstacle and is going to start accelerating. They do an extremely good job of making sure that people know they’re there, without being unnecessarily obnoxious.

kiliantics 4y ago

> Add to that the design of modern "luxury" cars which are soundproofed, fitted with anti-noise and blaring ICE systems to block the world out. The more I learn and think about this, the more it just seems absolutely insane to me how much we have given up for cars. Every horn and siren has to get louder, because the drivers have to hear them. No concern for others though, we must always appease the drivers first. Why can't we remove sound insulation in cars as a matter of policy? It would fix so many issues. Obviously removing most cars from cities would be a step better. In NYC, police and fire fighters are usually the stereotypical Jabronis who themselves drive the muscle cars and trucks to get to work (and park on the sidewalk outside the precinct). So of course they don't care about the noise they are pumping out on their sirens either. I live near a fire station in Brooklyn and it's truly deafening, even in the middle of the night when there's no traffic.

zip1234 4y ago
I'm pretty sure the sirens are just as loud as they are because the people in the completely sound insulated vehicles can't hear them otherwise.

dayvid 4y ago

Definitely this. As someone born in NYC who moved away as a teen and later moved back after a year, the NYC sirens are insanely louder compared to other city sirens. I'm not sure if it's due to the density of buildings, but I think they just set the volume louder. It's incredibly annoying, affects far more people than necessary and could be handled better.

ericbarrett 4y ago
You can always see multiple people plugging their ears when an ambulance goes down a busy street in NYC—it's a painful and resonant buzz in your skull if you don't. The sirens must be well past the level that causes damage.

klyrs 4y ago

I think there is a relatively easy solution, but it's hard to roll out today. Just as cell phones interruptively broadcast Amber Alerts, car radios should interruptively broadcast emergency vehicle sirens. There should still be an audible siren for pedestrians, but it could be much quieter. The trick is keeping the broadcast tight, without giving governments the ability to passively track the movements of all vehicles.

standardUser 4y ago

Having lived in city centers my entire life, if you had asked me to write a top 10 list of worst noise pollution sources, sirens wouldn't even make the list.