Definitely the Downtown Chicago Tornado Warning Siren

Probably the real one that I heard when russians attacked us on the first day of the war

We (my parents) bought a plot of land a long time ago. We built a house there, it took over a year. We finally finished it up and moved in. A few weeks later, we were in the living room. rrrrRRRRRRRwwwwooooaaahaaaaaaAAAAAAAAWWWWWWWWRRRRRRRRRRRRRRRRWWWWWAAAAAAAaaaaaaawwwwwwwwAAAAAAAAAAWWWRRRRRRRRRRRRRRRRRRRWWWWwwwwaaaaaawwwwwWWWWWAAAAARRRRRRRRRRRRRRRRAWWWWWWWwwwwwwwwwwooooaaahaaaaaaAAAAAAAAWWWWWWWWRRRRRRRRRRRRRRRRWWWWWAAAAAAAaaaaaaawwwwwwwwAAAAAAAAAAWWWRRRRRRRRRRRRRRRRRRRWWWWwwwwaaaaaawwwwwWWWWWAAAAARRRRRRRRRRRRRRRRAWWWWWWWwwwwwwwwwwooooaaahaaaaaaAAAAAAAAWWWWWWWWRRRRRRRRRRRRRRRRWWWWWAAAAAAAaaaaaaawwwwwwwwAAAAAAAAAAWWWRRRRRRRRRRRRRRRRRRRWWWWwwwwaaaaaawwwwwWWWWWAAAAARRRRRRRRRRRRRRRRAWWWWWWWwwwwwwaaawwwwrrrrrrrrr r r r r r r r r r r rr

The windows were rattling, which was neat because they were new and tightly sealed. The doors were rattling, the dishes were rattling

Down in the tree line, half hidden in a grove of trees along a boarder road one property over (maybe 800ft), there was a pretty damned big siren. I'm still somewhat shocked we never noticed it during the construction. No idea what it was, no indication what it was. Just a loud AF air raid style siren. Nothing on the news, no internet or cell phones back then.

After asking the neighbors, it was apparently the test siren for the local nuclear power plant (40 miles away), We had never been there on the first Tuesday of the month at 1pm, so we had never heard it being tested.

More recently, I moved into a new house about 2 years ago. (several moves later) and I was outside on a brisk day. All of a sudden, there was a tonal version of a klaxon, (think LOST) ERRRRRTTTTTT ERRRRRTTTT ERRRRRRRTTTTT ERRRRRTTTTT (3 second pause) ERRRRRTTTTTT ERRRRRTTTT ERRRRRRRTTTTT ERRRRRTTTTT (3 second pause) ERRRRRTTTTTT ERRRRRTTTT ERRRRRRRTTTTT ERRRRRTTTTT (10 second pause) (indistinguishable human speech) WAH ME FNDL WA NAW MAW WAH NENELE FAH WA NA. EFF WANAWA, ME FEDLE ME NO, ME NO MO NO FANALWE FWK THO

We live somewhat near a small airport with a National Guard base attached. In the summer, it's kinda quiet and far off as it's a couple miles away. When the air is very cold and the wind blows the right way, it sounds like they're doing it in my back yard with the exception that the speech is still absolutely unintelligible.

I've done a lot of work near/for/at chemical companies. They all have the regular slow-woop siren telling you to leave, preferably into the wind. And that's not a fun thing to hear, because they really don't like to push that button for any old thing.

But there's also the far worse "shelter in place" siren. When you hear it, it means shit is so fucked you can't even run away. And most places aren't exactly suited for riding out a chemical disaster.

Not necessarily an alarm in the literal sense, but the USA's EAS sound can send a shiver down my spine. Especially if you weren't expecting it

A bunch of people screaming in terror would probably be pretty terrifying: What's that? The gates of hell opening up to consume us all? No! It's just an emergency vehicle.

Classic air raid siren.

Silence, no help is coming and your robbed of the faint hope of social services discovering our ass before it's too late

Federal signal whoop sound.. Fairly standard equipment in heavy industry for emergency alarms.

Probably one that draws you toward it almost mystically.

The one that I heard early morning Feb 24 2022.

Terror? Carbon monoxide alarm. Less for the sound, and more for the mental strife after what you are 99% sure it is a false alarm... as that 1% doubt (that might kill you in your sleep) keeps you from sleeping.

The Danish Air raid sirenes allways gives me the creeps, I think it's the clear sound that gets me. Unlike other sirenes that has a harsha tone, the Danish ones have a almost sterile tone, convaying the feeling of "this sound is vary important, stop now and go Inside. Like a scary Teacher"

Starts at 0:15 and later has a "all clear" tone later on on youtubes

Then again it might just be because I had to listen to it as a kid, and I was a weird ass kid

Would it be Technology Connections doing an impression of a klaxon? https://www.youtube.com/watch?v=adD5oC2asXI

Purple alert

https://youtu.be/p97166Yt4X4?si=gFo4Ol_SKo94llDi

Whatever siren alerts you to the fact that nuclear missiles are inbound would be the most terrifying in my book.

The CRAM incoming incoming incoming. Gives many many people flashbacks and PTSD

https://youtu.be/IpMu3xgio9o?si=UOwajTEYeLNdQBML

Anything that wakes you up at 3am during a moment of political strife, I think.

One of these two: https://www.youtube.com/watch?v=M75VLQuFPrY

https://www.youtube.com/watch?v=kJLQ5pDpzHw

The multilingual emergency messages with the high pitched beeps on cruise ships.

I've never been on a cruise but I've seen a few videos and documentaries and always find this terrifying. You have nowhere to run to but a muster station. Like, you may drown while hearing a foreign language that you can't understand but is somehow telling you to GFTO.

The most terrifying siren is the one of a dive bomber.

Alien siren (Piped mirror) or War of the Worlds horn (Piped mirror)

The air raid sirens

I like the Thunderbolt 1000T, mostly because of LOCAL 58's Skywatching.

Moooooooooo

Man down alarm for the freezer at the distribution centre I work at. If that goes off in the office is ear splitting.

Where I live there are tries every this date, so when it really comes to your mind that its sounding awfully strong and long time than usually... It sure kicks you into another mood.