Unit 5.3

Sound Energy

• Sound energy is a type of energy produced when air particles vibrate because of another object's movement.
• Sound vibrations travel in sound waves.
• Sound can't travel through space because of limited particles in space.

Loudness

• Loudness is one way sound can be measured, as sound is a very complicated form of energy there are many other ways it can be measured. Loudness determines how loud a sound is in decibels (dB).
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Frequency

• Frequency on the other hand describes the number of waves travelled at a time. Frequency also determines pitch although they are different measurements, frequency is measured in Hertz.

Pitch

• The pitch describes the level of sound and is based on the frequency, the higher the frequency the higher the pitch.
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Wavelength

• Wavelength is the length of every sound waves and naturally is measured in metres per second, this also links to frequency, as the higher the frequency the shorter the waves are likely to be.

Sources of Sound

• Some sources of sound are your vocal cords, drums, guitars and others.You can speak because the flaps of skin around your vocal cords vibrate causing the sound.
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The Speed of Sound

• Sound can travel at different speeds depending on the surface of which it travels through, it travels fastest through solids, and slowest through gases because of the density of these surfaces. The higher the density the higher the speed of sound.

Echoes

• When sound hits a very solid surface it bounces off and you hear it in the form of an echo, this is only one of three ways in which sound energy can waste.
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Absorption

• Another way sound energy can be wasted is when it is absorbed into material such as fabrics and carpet and so on. This is the reason you don't often hear echoes in a classroom or in your home.

Sound Diffusion

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• Sound diffusion is when sound hits an uneven surface and disperses in all directions.