Changing Sound

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Changing Sound
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Review

• Back and forth movements are called __________

vibrations
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sound

• __________ is vibrations that you can hear.

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• The area where the air is pushed together is
  called a ___________

compression
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Sound waves

• ___________ are quickly moving areas of high and
  low pressure.

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• The height of a sound wave is called its
  _____________

amplitude
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• The width of a sound wave is called its
  _____________

wavelength
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• Sound waves move through the three parts of the
  ear. The brain processes the signals as
  __________.

sound
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• Sound waves move (away from or towards?) the
  person hearing the sound.

towards
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Sound

• Sound travels in waves.
• A sound can be
• Loud or soft
• High or low

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Loud or Soft

• How loud or soft a sound is this is called
  loudness.
• Loudness is a measure of the amount of sound
  energy reaching your ears.
• Whisper or shout

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Loud or Soft

• Louder more sound energy reaching your ears
• Softer less sound energy reaching your ears

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Loudness

• The loudness of a sound depends on how far the
  vibrating object is moving as it goes back and
  forth.
• Ruler on desk
• If you hit a drum harder or slam a door harder,
  you make a louder sound.

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High and Low Sounds

• You can make loud and soft sounds, but you can
  also make high and low sounds.
• Dog growl low sound
• Mouse squeak high sound

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Pitch

• How high or low a sound is pitch
• Pitch depends on how fast the source of the
  object is vibrating.

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Pitch

• Faster vibrations higher pitch
• Slower vibrations lower pitch

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Pitch

• Pitch can also be changed by changing the length
  of the object that is vibrating.
• Ruler on desk

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Sound Waves

• The height of the sound waves is called its
  amplitude.
• The width of a sound wave is called wavelength.

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Amplitude and Wavelength
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Changing Sounds

• Volume and pitch can be affected by changing the
  sound waves.

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Loud and Soft Sounds

• A loud sound has a high amplitude.
• A soft sound has a low amplitude.

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High and Low Sounds

• A high pitch has waves that are closer together
  (short wavelength).
• A low pitch has waves that are further apart
  (long wavelength).

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Changing Pitch

• Many musical instruments can be played at
  different pitches by changing the length of
  certain parts.
• A guitar or violin player puts his or her fingers
  down on the strings in different places.
• This changes the length of the vibrating strings.
• As a result, the guitar or violin plays different
  pitches.

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Changing Pitch

• Another way to make a different pitch is to
  change the thickness of the material that
  vibrates.
• A thin string vibrates faster than a thick string.

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Changing Pitch and Volume on a Guitar
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loudness

• ___________ is a measure of the amount of sound
  energy that reaches your ears.

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pitch

• ___________ is how high or low a sound is.

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louder

• More sound energy ________ sound

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softer

• Less sound energy ________ sound

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high

• Faster vibrations ________ pitch

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low

• Slower vibrations ________ pitch

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• When you change the amplitude (height) of a sound
  wave, you change its _________.

loudness
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• When you change the wavelength (width) of a sound
  wave, you change its _________.

pitch
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• To change the pitch of an object, you can change
  the _________ of a vibrating object or the
  _________ of a vibrating string.

length
thickness