Frequency

Sound vibrations can be described as a progressive sound wave which propagates in all directions as rings in water. The number of sound waves per second determine the frequency of a sound.

Frequency is measured in hertz (Hz): 

1 Hz = 1 vibration per second.

The low-frequency bass sounds have long, soft sound waves with few vibrations per second, while a treble sound has many vibrations per second.

Low-frequency bass sound		High-frequency treble sound

For instance, the wavelength in air for a sound wave with a frequency of 20 Hz is 17 m, but the same wavelength for a high-frequency treble sound wave with a frequency of 20 kHz is only 1.7 cm.

This means that the sound wave is inversely proportional to the frequency.

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