Sound Proofing in Vehicles

[Duke286]

Are there any laws pertaining to the level of noise that vehicles are required to allow through to the driver?

Some of you may recall a car commercial from a few years ago (I forget the brand) featuring a car stopped next to a construction site. The couple inside was able to have a normal conversation despite a contruction worker running a jackhammer right outside their door.

I remembered this commercial after several incidents occured to me where I was unaware of an emergency vehicle until the last second. Twice, ambulances were able to come behind me and get within 2-3 car lengths before I saw rather than heard them and once where I had to slam on my brakes to avoid a fire engine which came around a corner and passed through a red light into my intersection. In all three cases I had my windows up, air conditioner on full blast and my radio going (NPR not heavy metal or anything). And, before anyone asks, I've had my ears tested for work before and my hearing is fine.

So, are there any laws requiring how much sound has to be allowed to reach the driver of a vehicle? I live in Virginia but would be interested to know if this is the case anywhere.

Also, as an officer, what expectation do you have that people will actually be able to hear your siren, especially if they're not in a position to physically see you?

[Darin]

There are no such laws that I'm aware of. That's why we have emergency lighting as well as the siren. No matter how well they are sound insulated ALL cars have mirrors. Be aware of your surrounding while driving and use your mirrors.


When I 'm running lights and siren I anticipate other vehicles not seeing me. My expectation is that the drivers will use thier mirrors and scan their enviroment.

[scott715us]

I'm sure there's a federal motor vehicle standard that advises car makers must make vehicles to allow no more than "x" amount of decibles within the passenger compartment, but I couldn't point you to it. Sounds are not the only way one should be made aware of an oncoming/approaching emergency vehicle. If you are a safe driver, you should be constantly checking all of your mirrors and aware of your surroundings at all times. This is not to imply that you are "unsafe," as you join the mass crowds of thousands (possibly millions) of others who do not know we're coming until it's too late. A lot of this has to do with the technology over the last decade (cell phones, text messaging, blackberrys, GPS, MP3 players, DVD players, etc etc). That's why folks in the public safety field (fire, police, EMS) go through defensive driving classes. We expect the unexpected. I will never forget what my dad told me when I first started driving. He said, "if you drive on the roads as if everyone is out to hit you, you should be ok." I have been in a couple of minor fender benders over 17 years of driving, but for the most part I stick to this advice and it has served me well, both as a regular driver and when driving police & Fire/EMS vehicles.

[Creeker]

Are there any laws pertaining to the level of noise that vehicles are required to allow through to the driver?

Some of you may recall a car commercial from a few years ago (I forget the brand) featuring a car stopped next to a construction site. The couple inside was able to have a normal conversation despite a contruction worker running a jackhammer right outside their door.

I remembered this commercial after several incidents occured to me where I was unaware of an emergency vehicle until the last second. Twice, ambulances were able to come behind me and get within 2-3 car lengths before I saw rather than heard them and once where I had to slam on my brakes to avoid a fire engine which came around a corner and passed through a red light into my intersection. In all three cases I had my windows up, air conditioner on full blast and my radio going (NPR not heavy metal or anything). And, before anyone asks, I've had my ears tested for work before and my hearing is fine.

So, are there any laws requiring how much sound has to be allowed to reach the driver of a vehicle? I live in Virginia but would be interested to know if this is the case anywhere.

Also, as an officer, what expectation do you have that people will actually be able to hear your siren, especially if they're not in a position to physically see you?

I've never heard of any law setting specific levels of sound being permitted to pass through a vehicle for the driver to hear. If there was a law, I'd bet there is no penalty or enforcement clause to it.

Over the years I've seen various ideas and technologies show up attempting to solve the problem of sound insulated vehicles pertaining to emergency vehicles, but none have had much success. I think that the latest I've heard of is more realistic... "The Rumbler", which is placed on the emergency vehicle and is felt by the civilian driver rather than heard... but I have no real world experience with it.

I didn't "expect" anyone to actually be able to hear my siren, and drove appropriately.

[retdetsgt]

That would be a tough law on convertibles, wouldn't it?

[greg72982]

I remember in in-service training a few years back they said at around 50-60 mph you are actually moving faster than the audible siren. Because of this, those in front of you may not hear you so the emergency lighting would then come into play. There is a technical term for it which I cannot remember right now. This is probably a similar type of thing.

I think the bigger issue would be proving that the reason the driver the driver failed to yield was based on this feature, as opposed to something else (i.e. daydreaming, cell phone, stupidity). I'm not saying it would be impossible to prosecute, just very difficult.

[BJJVad]

I remember in in-service training a few years back they said at around 50-60 mph you are actually moving faster than the audible siren. Because of this, those in front of you may not hear you so the emergency lighting would then come into play. There is a technical term for it which I cannot remember right now. This is probably a similar type of thing.

I think the bigger issue would be proving that the reason the driver the driver failed to yield was based on this feature, as opposed to something else (i.e. daydreaming, cell phone, stupidity). I'm not saying it would be impossible to prosecute, just very difficult.

[retdetsgt]

I remember in in-service training a few years back they said at around 50-60 mph you are actually moving faster than the audible siren.

That was demonstrated to us in an inservice training once. We were put in a car on a track and driving 45 mph. We were to raise our hands and turn around when we first heard the police siren behind us. It was pretty shocking to see how close it was before we heard it. And this was w/o any radio or other distraction in the car.

Add a car radio with the volume at normal level and the siren has to be almost next to you before you hear it.

[pac201]

we have a code about how much noise comes out of a car, but not about how much is allowed in...

[retdetsgt]

we have a code about how much noise comes out of a car, but not about how much is allowed in...

Seems reasonable since deaf people are allowed to get driver's licenses.

[phantasm]

Beat me too it. I believe all marked NYPD police cars assigned to patrol in Manhattan South have them equipped. Manhattan South = all precincts south of 59th street (1, 5, 6, 7, 9, 10, 13, MTS, 17, MTN).

[Sgt. Slaughter]

Seems reasonable since deaf people are allowed to get driver's licenses.

Blind people too.

Must be a lot of 'em, somewhere. They've got the damn drive-thru ATM's with braille on the buttons.

[Creeker]

Blind people too.

Must be a lot of 'em, somewhere. They've got the damn drive-thru ATM's with braille on the buttons.

Along the lines of blind people, has anyone else heard anything about the blind organization that is up in arms about electric cars? It seems that they are concerned that the blind will get run over because they can't hear them coming.

[Sgt. Slaughter]

Nope. Haven't seen a thing.

(ba-dum CHING!)

[txinvestigator1]

I remember in in-service training a few years back they said at around 50-60 mph you are actually moving faster than the audible siren.

That is funny. ;). The speed of sound at sea level is approximately 1125 feet per second, or 770 mles per hour.


perhaps the doppler shift changes makes the frequency of the siren higher, and that is harder to hear, but you are not outrunning the sound waves when driving 60, or even 100.