How loud is the Chrysler air raid siren?
The 1952 Chrysler Air Raid Siren, powered by a 180 hp 331 cubic inch Hemi V8, was rated at 138 dB at 100 ft (30 m), and the 1942 Chrysler-Bell Victory Siren at 137 dB at 100 ft. Weighting is not stated in the sources, which report the manufacturer-era ratings.
- Level
- 137–138 dBunweighted sound level
- Distance
- 30.5 m100 ft (30 m)
- Daily limit
- About under 1 s a dayNIOSH, at the loud end
What the numbers mean
How it was measured. Rated output at 100 ft as reported by motoring journalists: 137 dB for the 1942 Chrysler-Bell Victory Siren, 138 dB for the 1952 Hemi-powered Chrysler Air Raid Siren. Weighting not stated; ratings from the period, not modern measurements.
The siren grew out of Bell Telephone Laboratories work during the Second World War. The Victory Siren used a Chrysler straight-eight engine and produced 137 dB at 430 Hz at 100 ft; the Cold War model used the new Hemi V8 and a three-stage compressor and was rated at 138 dB at 100 ft, at 460 Hz.
In a rural setting the sound was said to carry as far as 16 miles. These were the official civil defence sirens in many large US cities in the 1950s and 1960s, and some were in use until the 1970s.
How long is safe?
NIOSH recommends no more than under 1 s a day at 138 dBA (under 1 s at 137). OSHA's legal limit is 37 s. This level is not A-weighted, so the times are approximate: low-pitched sound measures lower in dBA.
| Level | NIOSH limit (85 dBA, 3 dB rule) | OSHA limit (90 dBA, 5 dB rule) | UK/EU 80 dB(A) action value reached after | UK/EU 85 dB(A) action value reached after |
|---|---|---|---|---|
| 137 dB | under 1 s | 43 s | under 1 s | under 1 s |
| 138 dB | under 1 s | 37 s | under 1 s | under 1 s |
Times are for a whole day’s exposure, with the rest of the day quiet. The workplace limits were written for adults at work, not for children. Work out a mixed day with the noise dose calculator.
Protecting your hearing
If you ever hear one run at a museum or enthusiast event, stand well back and wear plugs: at 100 ft it is still rated at 138 dB.
Earplug and earmuff ratings (NRR in the US, SNR in the UK and EU) are lab figures; real-world protection is usually lower. How to read the ratings.
Compared with sounds nearby
Using midpoints of each range. Energy multiplies by 10 every 10 dB; perceived loudness roughly doubles (why).
- White bellbird (125 dB max): this has about 18× its sound energy and sounds about 2.4× as loud.
- SLS rocket launch (Artemis I) (127–136 dB max): this has about 4× its sound energy and sounds about 1.5× as loud.
- Space Shuttle launch (142–155 dB max): it has about 13× the sound energy of this and sounds about 2.1× as loud.
- Saturn V launch (170–175 dB max): it has about 3,162× the sound energy of this and sounds about 11.3× as loud.
Questions
What is the loudest siren ever built?
The Chrysler Air Raid Siren is widely described as the loudest, rated at 138 dB at 100 ft.
How far could the Chrysler siren be heard?
Up to about 16 miles in a rural setting, according to published histories.
Sources
- The Loudest Air Raid Siren Ever Built Used Chrysler V8 Engines To Warn Americans Of Impending Nuclear Doom, Jalopnik. Supports: dB_high: 138 dB at 100 ft.
The device was also now even louder, rated at 138 dB at 100 feet.
Checked 2026-11-03. - The Loudest Air Raid Siren Ever Built Used Chrysler V8 Engines To Warn Americans Of Impending Nuclear Doom, Jalopnik. Supports: body: engine.
Upgrades included the use of the then-new 180-HP, 331-cubic-inch Chrysler Hemi engine and a three-stage compressor to increase output.
Checked 2026-11-03. - Chrysler Once Built The World's Loudest Air-Raid Siren, And It's Powered By A Hemi V8, The Autopian. Supports: 138 dB at 100 ft, 460 Hz.
This siren produced an incredible 138 dB at 100 feet, and the frequency was 460 Hz at 4.600 RPM.
Checked 2026-11-03. - Chrysler Once Built The World's Loudest Air-Raid Siren, And It's Powered By A Hemi V8, The Autopian. Supports: dB_low: Victory Siren 137 dB.
The siren produced 137 dB at a frequency of 430 Hz at a distance of just 100 feet.
Checked 2026-11-03. - Chrysler Once Built The World's Loudest Air-Raid Siren, And It's Powered By A Hemi V8, The Autopian. Supports: body: 16 miles.
In a rural setting, the siren’s call could travel as far as 16 miles
Checked 2026-11-03. - The Loudest Air Raid Siren Ever Built Used Chrysler V8 Engines To Warn Americans Of Impending Nuclear Doom, Jalopnik. Supports: body: in use to 1970s.
Some were in use up until the '70s.
Checked 2026-11-03.
This page is general information, not medical advice. If you have ringing in your ears, muffled hearing or any change in your hearing, see an audiologist or your doctor.