Speed of sound in water

Sound is one of the components of our life, and a person hears it everywhere. In order to examine this phenomenon in more detail, we first need to understand the very concept. For this it is necessary to turn to the encyclopedia, where it is written that "sound is elastic waves propagating in some elastic medium and creating mechanical oscillations in it." In a more simple language - it's audible fluctuations in any environment. From what it is, and the basic characteristics of sound depend. First of all - the speed of propagation, for example, the speed of sound in water differs from another medium.

Any sound analog has certain properties (physical characteristics) and qualities (a reflection of these signs in human sensations). For example, duration-duration, frequency-height, composition-timbre and so on.

The speed of sound in water is much higher than, say, in the air. Consequently, it spreads faster and is much more audible. This happens because of the high molecular density of the aquatic environment. It is 800 times denser than air and steel. It follows that the propagation of sound largely depends on the medium. Let us turn to specific figures. So, the speed of sound in the water is 1430 m / s, in the air - 331.5 m / s.

Low-frequency sound, for example, the noise produced by a working marine engine, is always heard a little earlier than the ship appears in sight. Its speed depends on several things. If the water temperature rises, then, naturally, the speed of sound in the water rises. The same thing happens with increasing salinity of water and pressure, which increases with increasing depth of the water space. A special role in speed can have such a phenomenon as thermoclines. These are places in which layers of water meet at different temperatures.

Also in such places a different density of water (due to the difference in the temperature regime). And when the waves of sound pass through such heterogeneous layers, they lose most of their strength. Faced with the thermocline, the sound wave is partially and sometimes completely reflected (the degree of reflection depends on the angle at which the sound falls), after which, on the other side of this place, a shadow zone is formed. If we consider an example where a sound source is located in the water space above the thermocline, then it's already lower to hear anything at all, it will not be that difficult, but almost impossible.

Sound vibrations that are released above the surface are never heard in the water itself. And vice versa occurs when the source of noise under the water layer: above it it does not sound. A bright example is modern divers. Their hearing is greatly reduced due to the fact that water acts on the eardrums, and the high speed of sound in the water reduces the quality of determining the direction from which it moves. This dulls the stereophonic ability to perceive sound.

Under the layer of water, sound waves enter the human ear most through the bones of the head's cranium, and not as in the atmosphere, through the eardrums. The result of this process is his perception at the same time with both ears. The human brain is not able at this time to distinguish between the places from which signals are received and in what intensity. The result is the emergence of consciousness, that sound rolls from all sides simultaneously, although this is far from being the case.

In addition to the above, sound waves in water have qualities such as absorption, divergence and dispersion. The first is when the sound power in salt water gradually comes to naught due to the friction of the aquatic environment and the salts present in it. Divergence is manifested in the removal of sound from its source. It seems to dissolve in space as light, and as a result, its intensity drops significantly. And the oscillations disappear completely due to scattering on all kinds of obstacles, inhomogeneities of the medium.