# Does this really annoying sound happen in your car, and what causes it, and is there a fix? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [May 23, 2016, 4:38pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466 "2016-05-23T16:38:03Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [May 23, 2016, 4:38pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/1 "2016-05-23T16:38:03Z")
When I have either or both back windows open more than a small crack, and at speeds between about 30 and 60 mph, a loud low frequency flutter develops. It is very intense, almost painful, and it’s something in the neighborhood of maybe 150 hertz. It seems not to be audible to passengers in the back seat, since they are invariably the ones who start it by opening their windows, but they show no real awareness of it. I thought it was something peculiar to my Mazda 3, but my sister says the exact same thing happens in her Prius. ---
**Author:** ![Channing\_Idaho\_Banks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/channing_idaho_banks/32/250_2.png) [@Channing\_Idaho\_Banks](https://boards.straightdope.com/u/Channing_Idaho_Banks)\ **Post date:** [May 23, 2016, 4:45pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/2 "2016-05-23T16:45:11Z")
Don’t ride with passengers. ---
**Author:** ![Macca26](https://avatars.discourse-cdn.com/v4/letter/m/13edae/32.png) [@Macca26](https://boards.straightdope.com/u/Macca26)\ **Post date:** [May 23, 2016, 4:45pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/3 "2016-05-23T16:45:34Z")
Yep, my last car did this. The only solution is to also open the front windows some, or open the back windows much more. I’m so accustomed to opening all my windows the same amount now to avoid it, that I haven’t even seen if it happens in my new car. But I also own a mazda3 so it must be the case! When I was a passenger in the backseat of my old car I could definitely hear it though. I think most people are just…well…they’re self-centered, to put it mildly. So if they aren’t really bothered by it they decide everyone else should be that way too. And may feign innocence when called out on it rather than apologize for something they don’t think they should be sorry for. But that’s a whole other kettle of fish. Anyway, I’m sure it has something to do with the air currents creating eddies around the car. Probably unavoidable. That, the noise, and air conditioning coming standard, is probably why seeing an open window on traveling cars is a rarity. ---
**Author:** ![Barkis\_is\_Willin](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Barkis\_is\_Willin](https://boards.straightdope.com/u/Barkis_is_Willin)\ **Post date:** [May 23, 2016, 4:57pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/4 "2016-05-23T16:57:55Z")
Yes, my car now does this to me in the driver’s seat if I only open the rear passenger window a few inches. If I crack any other window open it goes away. ---
**Author:** ![Lowdown](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Lowdown](https://boards.straightdope.com/u/Lowdown)\ **Post date:** [May 23, 2016, 4:59pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/5 "2016-05-23T16:59:28Z")
Yeah, just crack a different window or open one a little bit more. Done and done. ---
**Author:** ![PoppaSan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/poppasan/32/189_2.png) [@PoppaSan](https://boards.straightdope.com/u/PoppaSan)\ **Post date:** [May 23, 2016, 5:22pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/6 "2016-05-23T17:22:01Z")
My Avalanche does that when I open the sunroof. GM thoughtfully provided a pop up air foil to break the flow which mitigates that. At about 30 with the air foil manually pulled down, the noise and pulse is painful to me. My teenage son thinks it is cool - sadist he is. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [May 23, 2016, 6:40pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/7 "2016-05-23T18:40:45Z")
it’s called “thrum,” and it’s a problem on more and more cars. my understanding is it’s an effect of cars being more and more aerodynamic; the air passes over them much more smoothly, so open windows/sunroofs act like the old “blow air across the mouth of a beer bottle” thing. But the inside of the car is much larger, so the frequency of the sound is lower. You’re basically sitting inside a Helmholtz resonator. > **[Helmholtz resonance](https://en.wikipedia.org/wiki/Helmholtz_resonance)** > > Helmholtz resonance or wind throb is the phenomenon of air resonance in a cavity, such as when one blows across the top of an empty bottle. The name comes from a device created in the 1850s by Hermann von Helmholtz, the Helmholtz resonator, which he used to identify the various frequencies or musical pitches present in music and other complex sounds. > Helmholtz described in his 1862 book On the Sensations of Tone an apparatus able to pick out specific frequencies from a complex sound. The Helmhol... only things you can do is try to play with which windows are open and by how much, or fit those plastic “rain guards” onto the doors to try to disrupt the airflow a little. ---
**Author:** ![california\_jobcase](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@california\_jobcase](https://boards.straightdope.com/u/california_jobcase)\ **Post date:** [May 23, 2016, 6:57pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/8 "2016-05-23T18:57:58Z")
I have a Yaris and an Elantra that do the thrumming thing. I have had a Sentra, Celica, Ranger, and Festiva that didn’t. One detail the latter have that the former don’t is flow-through vents in the rear of the car. Anyone else have the same experience? ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [May 23, 2016, 7:20pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/9 "2016-05-23T19:20:21Z")
I once rode with someone in their Toyota Corolla with their windows doing that. It didn’t bother them but drove me crazy. ---
**Author:** ![Jophiel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jophiel/32/66_2.png) [@Jophiel](https://boards.straightdope.com/u/Jophiel)\ **Post date:** [May 23, 2016, 7:30pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/10 "2016-05-23T19:30:53Z")
My Mitsubishi Galant does it. It also can get an air current that causes my seat belt to vibrate against the side of the car and make an obnoxious sound. Two separate issues though and at least I can fix the seat belt one by stuff something between the seat belt and the car to silence that. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [May 23, 2016, 7:42pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/11 "2016-05-23T19:42:35Z")
> [@Channing\_Idaho\_Banks](#): > > Don’t ride with passengers. Or lock out their window controls. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [May 23, 2016, 8:08pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/12 "2016-05-23T20:08:19Z")
Here’s a [longer explanation](http://jalopnik.com/why-do-slightly-opened-car-windows-make-that-awful-soun-1447498738), but it pretty much says what has already been said above. And I like their solution to just drive faster until you are sufficiently past the resonance point. “But officer…” ---
**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\ **Post date:** [May 23, 2016, 10:19pm UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/13 "2016-05-23T22:19:54Z")
> [@control-z](#): > > I once rode with someone in their Toyota Corolla with their windows doing that. It didn’t bother them but drove me crazy. I first noticed it when driving my Corolla, and it DID drive me crazy. 🙂 ---
**Author:** ![seal\_cleaner](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@seal\_cleaner](https://boards.straightdope.com/u/seal_cleaner)\ **Post date:** [May 24, 2016, 12:29am UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/14 "2016-05-24T00:29:02Z")
My Tundra does it as well. ---
**Author:** ![elfkin477](https://avatars.discourse-cdn.com/v4/letter/e/a9a28c/32.png) [@elfkin477](https://boards.straightdope.com/u/elfkin477)\ **Post date:** [May 24, 2016, 1:13am UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/15 "2016-05-24T01:13:14Z")
> [@jz78817](#): > > The only things you can do is try to play with which windows are open and by how much, or fit those plastic “rain guards” onto the doors to try to disrupt the airflow a little. One of my dad’s cars had this problem… and the dealership eventually solved it by installing rain guards 😃 ---
**Author:** ![obbn](https://avatars.discourse-cdn.com/v4/letter/o/d6d6ee/32.png) [@obbn](https://boards.straightdope.com/u/obbn)\ **Post date:** [May 24, 2016, 2:24am UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/16 "2016-05-24T02:24:57Z")
Have that issue with both or Mazda Protégé 5 and Mazda 9. Using the window lock to keep the kiddos from lowering their windows solves the problem. I use it sometimes when I’m talking the kids and they aren’t listening. Roll the rear windows down, get the noise and it gets their attention. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [May 24, 2016, 6:50am UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/17 "2016-05-24T06:50:28Z")
I’ve experienced it in many different models. The reason some passengers or the driver may seem oblivious to it is that it’s a very similar phenomenon to the way air vibrates inside a flute to make a musical note. Within the volume of vibrating air, there may be vibration nodes (not really sure if that’s the right term) where there is relatively little thrumming to be observed - and other points where it peaks. ---
**Author:** ![Enola\_Gay](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@Enola\_Gay](https://boards.straightdope.com/u/Enola_Gay)\ **Post date:** [May 24, 2016, 6:59am UTC](https://boards.straightdope.com/t/does-this-really-annoying-sound-happen-in-your-car-and-what-causes-it-and-is-there-a-fix/755466/18 "2016-05-24T06:59:08Z")
This phenomenon drives me absolutely insane. The thud-thud-thud vibrating hurts my ears and sets my teeth on edge