as a former Toyota technician, i saw some of these "whistlers". Try changing the PCV valve with a new one from Toyota.
if that doesnt work (it probably wont) try removing the spars on the roof rack (if equipt). I see this from time to time and it will drive you crazy! also make sure the rear windows are completely shut.
dog whistling
It is quiet obvious when you have a turbo because when you accelerate you hear a whistling sound. The turbo noise is unmistakable.
could be a vacum leak in the engines intake or just road noise from the tires you cant hear when you step on the gas.
stop breathing...
"Did you hear that noise?" -or- "Did you not hear that noise I just heard?"
speaking from experience from ww2 Southampton bombing raids; bombs traveling at or above the velocity of sound; make a screaming, or whistling sound. The better you hear them; the more certainty it is not falling on you. The one that hits you you will not hear; for it gets there before its sound. ----
Past: Heard (e.g. I heard a noise) Present: Hear/hears (e.g. I hear a noise, She hears a noise) Future: Will hear (e.g. I will hear a noise)
You will hear them making a noise. Or you can just inspect them.You will hear them making a noise. Or you can just inspect them.
You need to pass the level called the Leap Hole in Chapter 2. Just hold down your left mouse button. You'll hear a little whistling noise, and all the goo balls will be attracted to your cursor.
the wind is so strong that is bllowing through the trees
Check the wheel bearings to start
There are some higher frequencies that only children can hear but adults cannot (the Viet Cong took advantage of this; children would assist patrols by telling them when they heard whistling. The patrol would shoot blindly straight up in the air and endanger the bombing aircraft that were flying over).