Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Are cars too well sound-proofed for drivers to hear emergency vehicles approaching?

  1. May 8, 2005 #1

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The favorite radio station thread reminded me of an experience while renting an SUV.

    I got an SUV as a rental vehicle last year for a visit to my sister (it came in handy for hauling around relatives and getting stuff to a park for my nephew's birthday). At one point, I had the radio on softly (my mom hates the car radio on and she was a passenger - that was somewhat fun to finally turn the tables on her, "I'm the driver and if I say the radio stays on, it stays on.") It was summer, the windows were up and the A/C on (I prefer windows down, but again, mom's a pain in the butt, and it was easier to turn on A/C than listen to her groaning about being too hot). Traffic was all stopped for a red light, and I watched an ambulance fly past with lights flashing...and I didn't hear a sound! There's no way they went through an intersection without a siren, but I swear, I didn't hear a thing. I had to crack the window to double check that they indeed had a siren on. I was shocked! Those things are so well sound-proofed, that you cannot hear a siren if you have the radio on and windows closed (I don't think the blower contributed much to noise, unlike in my little, non-luxury car where I have to keep the fan low to hear the radio over the blower). I didn't even have the radio playing loudly at all, unlike many others on the road who probably have far more noise inside their vehicles, like louder music, children squabbling, or whatever.

    I also recently watched a very near collision between a fire truck and an SUV. The fire truck was coming to the intersection, sirens and lights blazing, blowing their horn as they approached the intersection, and an SUV just kept driving right through the light. Other cars sitting at the intersection tried beeping their horns at the SUV as it showed no sign of braking. I was on the sidewalk and stood back from the corner fully expecting a collision. It was really a narrow miss. After my experience driving an SUV, I really had to wonder if that driver could even hear the sirens. Because of the buildings around the intersection, I know it's hard to see anything coming down the road, so you would have to have reason to stop before the intersection to see anything coming before entering, and the SUV had the green light, so no reason to slow down if they didn't hear the sirens.

    Anyway, this left me wondering if in an attempt to appease consumer demands for luxury cars that block out the road noise, have the cars become so well sound-proofed that they are unsafe? You need to be able to hear a siren, or a horn beeping, or that loud motorcycle in your blind spot (especially in a vehicle such as an SUV where there are large blind spots). People playing loud music also contribute to this problem in a less sound-proofed car. There are also deaf drivers. In all of these situations, even if you are an attentive driver, once one sense is cut out from detection of your surroundings, this seems to pose a real saftey risk.

    So, part 1 of this question: do you think this is a real problem? Have any of you experienced the same thing, either with the radio too loud or in a well-soundproofed vehicle that an emergency vehicle whizzed past with lights flashing and you never heard the siren?

    For part 2 of the question, what is the best way to resolve the problem? We can ask auto manufacturers to no make their cars quite so well sound-proofed, but I can't see them agreeing when there is consumer demand for it, nor does that help in the case of loud radios and deaf drivers. One thought I had, with no idea if such a thing is possible to design and install in a car, is some sort of external detector on a vehicle that would pick up on certain sound frequencies. Most car horns are tuned to the pitch of 'A,' right? Or is that myth? And emergency vehicle sirens seem to have a pretty well-defined pitch range as well that is not too common in the environment (or they could even be equipped with a transmitter at a specific frequency that would operate at an optimum range for drivers to respond to them and that this receiver in the cars would be able to detect - so that you're not picking up on the police car 4 blocks over, just the one approaching your intersection or coming up from behind you).

    Now, what would this receiver do when it detected sirens from an approaching emergency vehicle? Perhaps something like either turning off the radio, or cutting the volume down to the lowest setting so you can get an auditory cue, whether it's the radio going quiet, or finally being able to hear the siren over it. In addition, perhaps a flashing dashboard light, something to provide a visual cue to those who cannot hear the siren, either because of an overly sound-proofed vehicle, or deafness.

    Do deaf drivers have any sort of similar equipment already available to provide them with a visual cue of approaching emergency vehicles? At night, the flashing lights on emergency vehicles are easy to notice, but in bright daylight, they just aren't as noticeable, and if the vehicle is approaching from an intersecting street, they may be out of view until too late.

    Even if it isn't possible to replace the ability to detect all sounds, and it certainly won't replace the need to pay attention to your surroudnings, at least in the situation where there's an emergency vehicle approaching an intersection, it seems something is needed. Of course, unless it is required as an aftermarket installation, which may be impossible depending on what else is included in the same circuit as the radio, this could only be gradually implemented through installation on new vehicles, so is not going to be a quick or immediate solution to anything.

    Oh, and yes, I'm aware that there are some traffic lights equipped with devices that emergency vehicles can use to change the lights to stop traffic, but given that emergency vehicles sometimes need to make a wide turn, and into the opposing lane to get around stopped vehicles, it may be more useful to have something that alerts the driver that the don't just need to stop for a red light, but really should be getting over to the right and out of the way.

    In summary, here are the three main questions I've asked: Is this a problem that needs resolving? Is my idea of a receiver that provides an auditory and visual alert to a driver a viable solution to the problem? Is there a better or more easily implemented solution to the problem?
     
  2. jcsd
  3. May 8, 2005 #2
    You could have the ambulances carry radio transmitting equipment so if you have the radio on that's a plus, not a minus.
     
  4. May 8, 2005 #3
    I think, also that the fan may have had more to do with it than you think. I have an air filter that is absolutely worthless except that it produces white noise. When it's too loud outside I just turn it on and suddenly everything's blocked out.
     
  5. May 8, 2005 #4

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    In my own car, the fan is pretty loud, so no doubt it contributes in some (many? most?) cars. In that monstrosity I was renting, it was surprisingly quiet, but either way, having the A/C or heat on with windows closed is a pretty common thing, whether the problem was solely the sound-proofing or a combination of sound-proofing and fan noise.
     
  6. May 8, 2005 #5

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Wouldn't you need to be tuned to a specific frequency for that to help? Or do you mean as a supplement/modification to my separate receiver idea, to transmit a radio message through that instead of just quieting the radio? I was thinking the easiest thing would be a switch in the circuit leading to the radio to cut power to it (perhaps with a reset button so you can return to your music once alerted), or if it can be incorporated directly into the radio design, it could control volume, or do as you suggest, automatically tune to a frequency to provide an audio message.

    Maybe just a flashing signal on the dashboard is enough. Would there be a huge uproar and resistance to purchasing something if it could turn off your radio on you? Could tech saavy hooligans use it to transmit their own nonsense to your car radio? There's already some problems with the receivers on traffic lights due to people figuring out the frequency and misusing it to give themselves green lights and causing accidents by rapidly switching lights.
     
  7. May 8, 2005 #6

    Evo

    User Avatar

    Staff: Mentor

    Cars should not be soundproof and car radios should be limited to a low volume. You're driving a car for god sake not sitting in the lounge chair in your living room. You could kill someone.

    While we're at blocking out all outside noise and putting in surround sound stereos in our cars, why don't we get rid of those pesky windows? All that visual stimulation detracts me. :grumpy:

    I just want to get into my car, turn it on, put it in gear, lean back and close my eyes while listening to my favorite tunes and cruising down the highway.
     
    Last edited: May 8, 2005
  8. May 8, 2005 #7
    No, I mean transmitting the siren across all radio frequencies. So the siren comes over your radio.

    Any modification to the car is probably going to meet with resistance. It's the ambulances' problem and car companies aren't going to cooperate without a lot of incentive. Much better to put stuff on the ambulance than on the car.

    Another solution is just to make the siren louder, or to allow it to focus sound onto specific non-responsive cars (as I understand it this can be done).

    On a bicycle you can hear everything much better than in a car. That's the best solution from the consumer end. Plus, bicycles don't block the road.
     
  9. May 8, 2005 #8

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    :rofl: Yes, it seems people seem to just want to move their living room into their cars, doesn't it?
     
  10. May 8, 2005 #9

    Evo

    User Avatar

    Staff: Mentor

    And that's why there are so many wrecks, people forget that they're driving. Or should be driving and not applying makeup, reading (I know people that read books and newspapers while driving), talking on cell phones, smoking, eating (yeah, I'm guilty of that one, I've come close to getting in a wreck trying to keep my burger/taco/whatever from dripping on me). :redface:
     
  11. May 8, 2005 #10
    I've never had any trouble with eating while riding my bike.
     
  12. May 8, 2005 #11

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I'm not sure how easily that could be done relative to a single frequency, and it would probably meet with greater FCC resistance than having one dedicated frequency as an "emergency channel," such as is done with CB radios. If transmitting over all radio frequencies, it's also going to disrupt radios in houses that don't need to get out of the way! I'm sure the people who are already bothered by the sirens along the route to the hospital don't need yet another disturbance to their radio listening at home.

    But it's not just the problem of the ambulance. It's as much of a problem for the person hit by the ambulance as for the patient in the ambulance, or even you on your bike that the driver doesn't notice pedaling alongside them when they suddenly swerve to the side of the road when they notice the ambulance or fire truck bearing down on them at the last moment.

    Okay, you bike a lot, and surely you've been passed by fire trucks with sirens blaring with no metal, fiberglass or glass between you and that siren, right? Do you really think the sirens aren't loud enough? It's already deafening to a pedestrian or cyclist.

    A side benefit of this, that I really hadn't considered before until reading that comment, may be in situations where an ambulance is entering a residential neighborhood at night. You want to approach with lights flashing, but sometimes they turn off the siren to avoid waking up the entire neighborhood at 3 a.m. if there's nobody on the streets. If it's a call that they can respond to a bit slower (broken leg type things), then they do try to do this (and you can see the flashing lights from quite a distance at night). In those situations, the ambulance could avoid turning on the siren, but still have a way that any drivers would have an extra alert of the approaching ambulance in case they were developing late-night tunnel vision while driving.
     
  13. May 8, 2005 #12

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I have to agree. I'd prefer that the cars just not be sound-proofed and that radios not be permitted to go above a maximum volume, along with enforcing reckless/distracted driving laws (not just going after cell phone users, but everyone who is doing something other than driving). I guess I just don't expect that to actually happen. The potential downside to something like an extra warning system is that it may lead to more recklessness as people allow it to be another substitute for paying attention to the road around them.
     
  14. May 8, 2005 #13
    If people are listening to the radio in their houses when the blaring siren goes past, it won't make any difference--they'll just be hearing the siren from two places, not a big difference. The only people it would make a difference to would be people listening to the radio in soundproof booths. There are not very many of those.

    An "emergency channel" would entirely defeat the point. The point is to get the siren across to people who are listening to the radio in their cars, not people who are listening to the "emergency channel" in their cars.


    Sound-focused sirens are probably the best idea. Focused sound could concentrate specifically on the area that the ambulance needed to have clear, in addition to a general diffuse siren that people could hear.
     
  15. May 8, 2005 #14
    You know, on a bicycle you can hear the sound of cars moving around you. You use your ears to find out what's around you.
     
  16. May 8, 2005 #15

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Um, in the houses, they are allowed to use soundproofing material to drown out the sirens, so no, it wouldn't have to disturb them to the extent having the radios all blare a siren would. I'm trying to stick within the realm of reality and what the general public might actually agree to.

    Okay, let me try this again...by an "emergency channel" I didn't mean for transmitting on the car radio, but for the external receiver to be tuned to that would display the warning, cut the radio, whatever it does. I don't think it would be useful for transmitting a message over a car radio because nobody would tune to that frequency on the radio (unless you're an ambulance chasing lawyer, perhaps :rolleyes:).

    I think you've missed the point. I'm talking about the vehicles that are out of sight range of the approaching emergency vehicle -- the ones coming from the intersecting road from both directions, perhaps with buildings obstructing the view; these are the vehicles that are unaware they need to slow down before they get to the intersection and need earlier warning. Besides, sirens already are pretty directional.
     
  17. May 8, 2005 #16

    Moonbear

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I do know that. That's half the point I've been making, that car manufacturers seem to be doing more and more to eliminate hearing as a viable means of detecting what's happening around you. There is also a deaf population that does not have advantage of this sense. The topic here is about motor vehicles with sound proofing and radios, not about bicycles or debating alternative modes of transportation. If you want to discuss alternative transportation, please do so in another thread.
     
  18. May 8, 2005 #17

    Evo

    User Avatar

    Staff: Mentor

    It's also important to hear the siren and KNOW which direction it's coming from. If you see or hear some alert and don't know where the vehicle is coming from, how will you know what to do?

    How about someone honking their horn at you to let you know you're about to hit them? Or the sound of screeching tires letting you know something's wrong and you need to assess what's happening. I've avoided a couple of collisions because of the sound of screeching tires.

    There are too many reasons you need to hear what's going on around you when you drive.

    I live in tornado country, trust me, you want to hear that siren when it goes off, it may be the only chance you have. They recently replaced the old siren on my street with one that will wake the dead. The one they had before couldn't be heard with the windows closed and the airconditioning on, which is the time of year that tornadoes occur. If you're driving, you want to hear that siren, once you're in it's path, it's a bit too late.
     
  19. May 8, 2005 #18
    Very few people use soundproofing to that extent in their houses. An ambulance-mounted radio transmitter is a perfectly good idea. Any modification to the cars as opposed to the ambulance is not going to happen without drawn-out legislation. But it's easy to mount a radio transmitter in an ambulance. When you get down to it, if making sure people can hear the ambulance is less important than making sure a very few people listening to the radio in soundproof rooms don't hear an annoying siren, then maybe everything is fine already. On the other hand, if you think the importance goes the other way, then we should put radio siren transmitters in ambulances.

    If there are buildings in the way, then I suppose the ambulance could reflect focused sound off buildings to target spots around corners. But for the majority of cars, focused sound would work fine.
     
  20. May 8, 2005 #19
    I think you're just jealous that you didn't come up with the radio idea first.
     
  21. May 8, 2005 #20

    Danger

    User Avatar
    Gold Member

    I think that the transmitter/receiver idea is a very good one. As Evo pointed out, directionality is important too. Maybe an ADF circuit should be included in the receiver so it can point to where the siren is.

    BicycleTree, you seem to be totally ignoring the vast number of people, including me, who don't listen to the radio as well as the aforementioned deaf ones. Transmitting to an inert radio won't offer any visual cue.
     
    Last edited: May 8, 2005
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Are cars too well sound-proofed for drivers to hear emergency vehicles approaching?
  1. Emergency (Replies: 5)

  2. Sound-Proofing Room (Replies: 2)

Loading...