tornado sirens in downtown chicago

[Georges]

Here's what they sound like in St Louis.

https://www.youtube.com/watch?v=yVBkd8Bu-q8

Not as creepy as others.

[Ad Bot]

[Blockzillahead]

i think they sound like that because they dont want to confuse it with something else lets say a really loud ambulance or whatever

[SgtDaemon]

someone loop this please

[xbox 360 fan]

The siren, which is in the center of the city, actually has one tone to it. It sounds like that because it is echoing off of all the buildings and surfaces. It has a name.

Doppler Effect I think it's called.

[XR-7]

Doppler Effect I think it's called.

Doppler Effect iirc is where signals are sent at an object and bounces back to a receiver which then picks up information about the object such as shape, velocity, and location. Hence Doppler radar.

[xbox 360 fan]

Doppler Effect iirc is where signals are sent at an object and bounces back to a receiver which then picks up information about the object such as shape, velocity, and location. Hence Doppler radar.

That's just radar, this is EFFECT

http://en.wikipedia.org/wiki/Doppler_effect

[Foxscotch]

Doppler Effect I think it's called.

no

Doppler Effect iirc is where signals are sent at an object and bounces back to a receiver which then picks up information about the object such as shape, velocity, and location. Hence Doppler radar.

well
ok
no-ish
the doppler effect is "the change in frequency of a wave (or other periodic event) for an observer moving relative to its source"
but doppler radar is what you described. like the entire post is about doppler radar. not the doppler effect

[HerpaDerp]

pretty creepy, but the ones i hate the most are WW2 air raid sirens

https://www.youtube.com/watch?v=msX8iULEQgA

they sound weird af and although they are normally used in video games, this stuff was the real deal and meant you were gonna be blown to pieces.

[Taboo]

I'm playing Type-0 and for some reason there's an air raid siren whenever you have a mission to complete. Pretty ballsy, SqEnix.

[Jairo]

Tornadoes can happen in any of the 50 states at any time of year

I'm pretty sure tornadoes can happen elsewhere in the world, too

pretty creepy, but the ones i hate the most are WW2 air raid sirens

that reminds me of jericho's Annoying Orangeet, more commonly known as the stuka siren

[Kimon²]

I'm pretty sure tornadoes can happen elsewhere in the world, too
that reminds me of jericho's Annoying Orangeet, more commonly known as the stuka siren

psychological effect?

[Foxscotch]

psychological effect?

yes
"upon the leading edges of its faired maingear legs were mounted the Jericho-Trompete ("Jericho Annoying Orangeet") wailing sirens, becoming the propaganda symbol of German air power and the blitzkrieg victories of 1939–1942"

[Taboo]

psychological effect?

Meant to freak out targets as the bomber headed in.

[Jairo]

psychological effect?

the germans were very good at making terror weapons to demoralize enemies

the nebelwerfer is another example

hearing something like the stuka screeching above the bustle of a fight would scare you stuffless

or rather just the sight of a giant loving airplane diving and screaming

[HerpaDerp]

psychological effect?

yes the main purpose for most air raid sirens was to strike absolute terror into those on the ground who heard it.

it was used to strike the fear that you were going to be killed, and that by the time that siren is sounded, it's too late

although in the beginning it was just a combination of flying maneuvers that caused such sounds, eventually it was focused on as a psychological effect
hope that explains it.