Weird sound when windows are rolled down

I just bought a new 2010 Camry last July. Yesterday, when I was driving down the hwy with my back windows rolled down, I noticed a sound that goes ba-ba-ba-ba- really fast. The sound got louder as I drove faster to the point where it was absolutely deafening. It sounds kind of like when you drive over rumble strips… When I rolled my windows back up, the sound went away. When I roll my windows back down, the sound comes back. Note: this only happens with my back windows too. When I roll up my back windows and roll down my front windows, it sounds normal… no wierd noise at all. I’m sure this is not supposed to happen, but I’m not sure if this is a major problem that I should be concerned about or not. It is very disturbing though since my car is new.

Has anyone else experiencd this? Does anyone have an idea what could be the problem? Thanks!! =)

I don’t know that you’d say it is “supposed” to happen - as in it was made that way purposely. Its more of a derivative effect of something else and is perfectly normal. Just about every car does this.

I’m sure someone smarter than me can explain exactly why but it basically has everything to do with aerodynamics designs - you more or less have two fast moving streams of air slamming into each other in the back seat.

For the sake of aerodynamics, modern cars are designed to be driven with the windows closed. Opening the windows–particularly the back ones–disrupts the aerodynamic air flow and will produce this noise effect on virtually all modern cars to at least some extent. The 2010 Camry may be worse than average in this respect, but it is a factor that will affect every Camry–not just yours.

There is really nothing that you can do about this situation, except to avoid driving at high speeds with the rear windows open or to buy an older car that does not exhibit this modern phenomenon.

Our 2008 Caravan does the same thing> If I just crack open one of the front windows the noise goes away.

What they said. My '03 Camry is the same way. I have two other newer vehicles that also exhibit the phenomenon but to a lesser extent. If you play with the window positions, you can minimize the effect by mis-matching the impedance and eliminating or minimizing the resonant tone.

It’s called buffeting.
The air flow is atempting to pack into the interior until…
There’s too much, so some has to force its way out…
then more wants in…
until too much wants out.
in
out
in
out
bababababababa

Excellent explanation, as usual.

I’m sure Zwicker would agree
http://www.sae.org/technical/papers/1999-01-1821

Here’s some other sources of information on the subject
http://www.sae.org/servlets/PaperEvents?OBJECT_TYPE=PaperEventsInfo&PAGE=getPapers&GEN_NUM=36103&TOPIC=Noise/Vibration/Harshness (NVH)&TECH_CD=NOISE

I have heard this many times with many cars. It happens with the correct combination of vehicle speed, wind direction and window opening. Another description is “Organ Piping”.