Please note, many of these recordings are 10+ years old. For many more siren recordings, please visit YouYube.com as there are well over 5,000 videos of sirens on there!
Do your family a favor and use headphones :-)

Video Clips
0:58 1.2MB Federal 2001 Movie from Williamson, TN (MPEG Movie)
  2.0MB American Signal's T-128 Test Movie (MPEG Movie)
0:39 1.6MB Clip from "The Time Machine" featuring the sounds
of a Carters siren, and a cameo shot of the Federal Model 5 housing.
This movie requires Quicktime 5.0 or newer with the Sorenson-3 Codec
  1.0MB Civil Defense film showing the Chrysler siren and an air raid drill
Recorded from PBS's "Race for the Superbomb"
This movie requires Quicktime 5.0 or newer with the Sorenson-3 Codec
0:32 4.6MB "Let's Face It" (MPEG Movie)
A Federal Civil Defense PSC featuring the Thunderbolt and Model D sirens
0:17 515K British WWII A.R.P. Newsreel clip featuring the Carters siren
This movie requires Quicktime 5.0 or newer with the Sorenson-3 Codec
My Recordings
Recorded with a Sony TCD-D8 DAT and AT822 Microphone
0:29 575.7K Federal 7T dual-tone air raid siren
Recorded from outdoors with siren housing removed.
0:31 496.7K WWII Carters British hand-crank air-raid siren
0:18 292.2K Federal G-1 hand-crank siren
0:24 391K Federal Model 2T
498 / 622 Hz Recorded outdoors
1:53 1.8MB Brattleboro Thunderbolt 1000 in alert mode, part of the Vermont Yankee Nuclear Plant warning system
1:52 1.8MB Brattleboro Thunderbolt 1000 in attack wail, part of the Vermont Yankee Nuclear Plant warning system
Not My Recordings
These recordings are mostly donated or found on the web
4:05 2MB Federal 500SHTT 10/12 port Alert
Recorded by Ron Wilbanks
0:22 351.1K ACA P-50
Recording appears to have been shortened crudely, but still very worth listening to
2:29 1.2MB Model 3
This is a strangely drawn-out 3-cycle test (lack of horsepower)
Recorded by Jason Chrismon in his home town
1:24 662.9K STH-10 attack wail, donated by Mike Stalnecker
MPEG'd from an 8-bit 8kHz file, so may not sound true to the orignal siren
1:16 751.1K Federal Model 7, 8-port version (best guess) donated by Brett Jones
0:45 448.9K British Carter siren giving a 30 second All Clear
This was labeled as British where I found it, but some people think it is a slow 2T22
0:32 318.3K SD-10 2-cycle test from uvfr.org
1:58 924.7K 3T22 high-low wailing fire signal contributed by Brett Jones
1:35 750.5K 3T22 in high-low mode recorded and contributed by Brett Jones
1:04 504.2K 2HP ACA Screamer, single-tone, recorded by Brett Jones
Distorted during recording, but you can still get an idea,
and you can hear the capacitor motor's switch kill the spin-down
0:55 1.1MB Model 2 sounding the attack warning
1:19 1.6MB Unknown hand siren 1
0:34 663.2K Unknown hand siren 2
0:19 383.6K Unknown hand siren 3
1:30 879.4K Yugoslavian air raid warning
1:19 1.4MB Long attack signal (single-tone) with other sirens audible in the background
0:55 1.1MB 2T22 noon test in Alliance, Alberta Canada
Recorded by Sonic Studios at Simon Fraser University
1:15 1.2MB Sirens in Belgrade
Recorded by Nee in Yugoslavia
0:56 884.9K More sirens in Belgrade
0:38 378.8K Federal SD-10
Terrible old recording, not indicative of actual sound.
0:35 276K Federal Model 2 from On-stage Noise Division
0:40 318.2K Fire siren, single-tone
0:20 203.3K Fire siren, single-tone
0:44 438K Air raid siren, single-tone wailing
0:42 419K Sentry 3V8, single-phase 5HP capacitor-start motor version
Note that you can hear the capacitor motor's switch abruptly slow the siren
when it re-engages during the winding down (after the last wail).
0:43 422.9K Sentry 40V2T
1:37 1.5MB Sterling M
3:09 1.9MB Thunderbolt 1000 Alert
1:08 537.3K Thunderbolt 1000T
1:19 775.4K Thunderbolt 1003 steady high-low fire signal
0:59 351.0K Thunderbolt 1003 wailing high-low fire signal
Notice that this 1003 has one inoperative solenoid on the low note.