Sound

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• Sound

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• A sound is produced by the initiation of a
  succession of compressive and rarefactive
  disturbances in a medium capable of transmitting
  these vibrational disturbances.
• Particles of the medium acquire energy from the
  vibrating source and enter the vibrational mode
  themselves.
• The wave energy is passed along to adjacent
  particles as the wave passes through the medium

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Examples of Vibrating Elements

• Vibrating Reeds. Ie clarinet and saxophone.

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• Strings. Ie. Guitar, vocal cords

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• Membranes. Ie. Drum, loud speaker

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• Air columns. Ie Pipe organ, flute

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Frequency Range

• The frequency range in which sound occurs is
  called the sonic spectrum.
• The lower limit of the sonic spectrum is not well
  defined. For example, in an earthquake the
  frequency may only be a fraction of a wave per
  minute.

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• The upper limit of the sonic spectrum is well
  defined.
• For waves traveling with a constant velocity, as
  frequency increases, wavelength decreases.
  Eventually, wavelength will become so small that
  a particle will not be able to transfer its
  energy to adjacent particles.

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• For ordinary temperatures and pressures, the
  upper range of the sonic frequency range is of
  the order of 109 hertz in a gas.
• For solids and liquids, the upper range of the
  sonic spectrum is higher because the particles
  are more closely spaced together.

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Definitions

• Audio range a range of compression wave
  frequencies to which the human ear is sensitive.
  For humans, the audio range is 20 hz 20000 hz.
• Ultrasonic sound waves with frequencies above
  the audio range.
• Infrasonic sound waves with frequencies below
  the audio range.