Atomic bomb explosion

‘What?! I can’t hear you!’ The loudest sounds ever recorded

Image credit: Diomedia

The biggest clamours most of us will experience are things like fire alarms and jet engines, but the loudest noises in existence would do far worse than make you wince. Here are some of the most ear-shattering sounds ever recorded.

Krakatoa eruption of 1883 (310dB)

On 27 August 1883, the volcanic island of Krakatoa, which sits between the islands of Java and Sumatra in Indonesia, erupted. Regarded as one of the deadliest and most destructive volcanic events in recorded history, the sound of its explosions could be heard clearly almost 5,000km away. It was said to clock in at 310dB at the source and 189 to 202 dB from five kilometres away. Residents of New Guinea and Western Australia reported hearing “a series of loud reports, resembling those of artillery in a north-westerly direction”. Meanwhile on the island of Rodrigues in the Indian Ocean (4,800km away), locals reported hearing what sounded to them like the distant roar of heavy gun fire.

Tsar Bomba (224dB)

The Soviet RDS-202 hydrogen bomb (code name Ivan or Vanya) became known to the rest of the world as the Tsar Bomba. Tested in 1961, the bomb was 8m long and weighed 27,000kg. Its explosion equalled 50 megatonnes of TNT, and ripples from its test explosion could be felt all around the world.

The Hiroshima and Nagasaki bombs of 1945 destroyed cities in an instant – but the Tsar bomb was 3,300 times stronger than that and is considered the strongest sound every produced by mankind, with the most reliable figure suggesting it clocked at 224dB.

Saturn V Rocket (204dB)

Developed for the Apollo programme, the Saturn V rocket was the tallest and most powerful spacecraft to be successfully flown by Nasa. It launched 13 times, and could propel 118 tonnes of payload into low Earth orbit or 43.5t to the Moon.

Its first stage, called the SI-C stage generated around 33,000 kN of thrust for lift-off, therefore creating quite a bit of noise, and was recorded to produce sounds of 204dB.

Chelyabinsk meteor (180dB)

Type ‘Chelyabinsk meteor’ into YouTube and see the handful of Russian dashboard cameras that caught this event. A force equal to 500 kilotonnes of TNT shattered glass and tossed debris throughout the city, injuring more than 1,000 people. Big booms typically emit a lot of far-reaching ruckus called infrasound, which is too low-frequency for human ears to pick up. Chelyabinsk hit sensors 9,000 miles away in Antarctica. Calculated measurements have suggested the explosion clocked in at 180dB from three miles away.

Howler monkeys (140dB)

Found swinging in the trees of the Central and South America rainforests, it’s hard to believe that such small animals can make a sound that’s the combination of an air-raid siren and a heavy-metal guitar solo. Howler monkeys have what’s called a hyoid bone in their throats that has evolved to become a large resonating chamber to amplify their roars. These roars have clocked in at 140dB at the source. Why do they howl like this? Only the males howl, and use it to let other howlers know their location and to defend their territory, as well as possibly for mate-guarding. According to the Guinness Book of World Records, their vocalisations can be heard by humans up to 3 miles away.

Republic XF-84H ‘Thunderscreech’ (est 200dB)

Created by Republic Aviation for the US Air Force in 1955, the XF-84 experimental fighter never saw combat, but it left behind plenty of casualties due to how loud it was. The noise levels for the Thunderscreech were never officially measured, but it could be heard 25 miles away. The propeller tips sped along at over 900mph and so produced a constant sonic boom, hence the noise. It was notorious for inducing nausea and migraines for crew and ground crew.

Large European Acoustic Facility (LEAF) (154dB)

LEAF is the most powerful sound system in Europe, and is part of the ESTEC Test Centre in the Netherlands. One of its walls is embedded with a set of sound horns that can produce a range of noise up to more than 154dB when nitrogen is shot through them. The system can only be turned on once all doors are sealed shut. Steel-reinforced concrete walls safely contain its noise, coated with epoxy resin to reflect noise to produce a uniform sound field within the chamber.


A quiet place

The quietest sound theorised by mathematicians is Brownian motion: the movement of particles in a gas or liquid, clocking in at -23dB. The next step would be a vacuum, like space, with a complete absence of sound. The world’s quietest place, however, is not far from Brownian motion.

Hidden in the depths of Building 87 at Microsoft’s headquarters in Washington lies a specially constructed anechoic chamber. The silent space, created by the tech company for optimal audio and device testing, has the lowest sound recorded in a room, clocking in at -20.6dB.


Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles