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The loudest known sound, recorded in modern times, was the eruption in 1883 of the volcanic island of Krakatoa, located in the Dutch East Indies. The volcano erupted with such force that it could be heard in Australia, two thousand miles away. The explosions lasted for 36 hours, and blew off half the island. The final outburst had enough sound energy to circumnavigate the Earth 7 times before it eventually dissipated.

The softest sound which can be detected by the human ear occurs in the range of about 0 to 5 decibels, which is equivalent to the sound of air molecules moving inside the mouth of a drinking glass. By definition, the softest sound that can be detected by an acoustic sensor requires the minimum amount of energy which is necessary to produce a vibrating wave motion in a medium.

The highest sounds, known as hypersounds, are generated at frequencies which vibrate at billions of times per second. These microcycles include the oscillation of the tiniest known particles of matter.

The lowest sounds are produced by large objects, and are known as infrasounds. Infrasounds have very long wavelengths with a single vibration occurring within a period of millions of years. These include planetary, interplanetary, stellar, galactic, and intergalactic cycles. The very lowest sounds are generated in large intergalactic gas clouds caused by the galactic wind and stellar explosions.


catalog of sounds >> page 1 | 2 | 3 | 4 ......

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