Sounds of Nature

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Atmospheric acoustics to study the characteristics of distribution and hearing sounds in the atmosphere. Sound is called an oscillatory motion of the particles of an elastic medium with frequencies from 16-20 to 20 000 Hz, is perceived by our hearing organ. Around the sound source is a vicious wave that spreads out in all directions. Separate sound wave is a compression and air distribution arising from the vibrational motion of the molecules of the gas along the path of the wave.

In nature, there are a variety of sound effects, the origin of which is related to meteorological and geophysical processes. Known and most studied sound meteorological phenomenon origin – thunder that usually accompanies lightning strikes. Education thunder explained as follows. Along the way there is a sudden lightning heating and therefore a strong expansion of the air, like a loud explosion. This expansion and cause a shock wave moving in the atmosphere and reach the Earth’s surface.

Thunder usually not perceived as a single sharp sound (which is rare), but as a series of strokes, called peals that are different intensity and last for a few seconds, creating a continuous rumbling sound. Duration and thunder depend mainly on the length and affectation way zipper. Sharp and short shots occur in cases where the lightning discharge occurs near the observer, and in particular at small length of the lightning channel (when lightning strikes the ground). The greater the distance from the observer to the lightning, the long and winding its path, the longer and is rolling thunder. This is because there is thunder on the entire trajectory of lightning almost simultaneously, but over long lightning channel sound from various points it reaches the observer is not at the same time though with varying intensity. In addition, single channel lightning through several consecutive digits and they produce sounds merge, increase the duration, create thunder. Finally, in the formation of thunder plays a role reflected sound (echo) as from the earth’s surface and the clouds and the interfaces of air masses. Learn more about forest sounds.

Despite the great power of the sound source, the range of hearing thunder rarely exceed 20-25 km. This is because, firstly, the thunder occurs when all the twisting path of lightning and its energy is dissipated in this way, and secondly, the thunder always occurs when weather conditions are unfavorable for hearing.

Over the interval of time between the flash of lightning and thunder can determine the distance from the observer to place a lightning strike. To do this, this time multiplied by the average speed of sound equal to 332 m / s.

Sound effects, such as the howling wind, the hum of wires, the noise of the forest, the rustling of the willow, and others are explained as follows. In flowing air stream of solid objects near each of them there are eddies of air. If the vortex shedding from the obstacle occurs with a frequency of perceived ear (which occurs at high wind speed), there is a sound wave. The higher the wind speed, the higher the tone of the sound produced. And as the wind gusts usually, it creates a large number of different sounds.

In flowing air is the tone of the sound also depends on the diameter of the oscillating wires, and the power of sound – the degree of tension it. Particularly strong buzz wire observed in winter with severe frosts, when the wires, cooling, shortened and taut.

Sounds that occur when falling rain and hail at objects or soil, moving snowflakes on snow fields when moving sand masses, caused collisions of individual particles and vibrations of the surface on which they fall or along which they move.