How is sound in air different from sound in water?

Sound waves can travel through solids, liquids and gases. In fact, they do not exist unless there is something for them to travel around. How sound travels through water is different from how it travels through air, but what is the difference?


Sound is measured in amplitude. High noise is described as high amplitude, but quieter or softer has low amplitude. The word & # 39; amplitude & # 39; actually refers to the pressure change caused by a sound wave – loud noises create more pressure and carry more energy than lower amplitude.

Energy and power

& # 39; Intensity & # 39; is the name given by a quantity emitted by a sound wave over a particular area and is measured in watts per square meter. The higher the water, the more & # 39; intense & # 39; The sound wave.

Decibel and relative volume

Scientists want to work at a relative volume using proportions. For this, sound is measured in decibels (dB), rather than watts per square meter. Reference levels are different for water levels and air levels.

In water, scientists use the reference concentration of 1 microPascal (μPa) pressure, while in the air, the reference concentration is 20 microPascals, the minimum concentration that young adults can comfortably hear.

How sound waves travel through air and water

You cannot measure the strength of a wave without taking into account the substance or medium it is passing through. The density of this material is affected as air is significantly less dense than water. Similarly, the speed at which sound is traveling must be considered as it travels much faster through water than through air.

The denser the medium and the faster the sound waves, the lower their intensity. Because sound travels faster than water, and where water is more dense, sound has a lower concentration of water than it does in air.

How relative intensity plays its role

Sound waves with the same strength in air and water, when measuring in watts per square meter, actually have different relative strengths when you & # 39; measures in decibels. The difference is 61.5 dB, consisting of 35.5 dB due to different sound speeds and densities, and 26 dB due to different reference pressure. This needs to be subtracted from quantities measured in water to compare them directly with points in the air, which gives pure strength.

Reports sound levels

When reporting sound levels, you should not use just decibel as your unit of measurement. You also need to improve the reference level. In water you measure the intensity of the & # 39; dB re 1 μPa & # 39;, and in audio you measured & # 39; dB re 20 µPa & # 39;.