Sound

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Sound

• Properties and Interactions

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How Do We Produce Sounds?

• Vibrations are key!!!!!

Vibrations the complete back-and-forth motion
of an object
Often Created By A Speaker
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Example of a Speaker

1. Vibrations begin at the sourcethe speaker

B. Vibrations move in wavesaway from the source

1. Vibrations continue to move in waves away from
   the sourcein compressions and rarefactions

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Sound Waves are Longitudinal

• Remember COMPRESSIONS and RAREFACTIONS!!!!

Compressions
SOURCE
Rarefactions
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Need For A Medium

• Medium a substance through which a wave can
  travel

Solid, Liquid, Gas
Sound cannot travel in a VACUUM!!!!
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Speed of Sound
The speed of sound depends on the medium
The speed of sound is constant through a medium
as long as the properties of the medium are
constant
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Changing The Speed Of Sound
The biggest property of change is TEMPERATURE!!!
Colder the medium the slower the speed of sound
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Whudyou Say Willis?
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What!?!?!?
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Yeah!!!!!

• When you listen to things at too loud a
  levelthese cilia (hairs) continue to vibrate and
  lead to a ringing in your ears

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Pitch
Pitch how low or high you perceive a sound to be
Depends on Frequency
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Frequency and Hearing
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Doppler Effect
Doppler Effect The apparent change in the
frequency of a sound caused by the motion of
either the listener or the source of the sound
The frequency doesnt actually changeits only
sounds like it does
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Loudness
Loudness how loud or soft a sound is perceived
to be
Larger amplitude Louder Sound
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Reflection of Sound Waves
Reflection the bouncing back of a wave after it
strikes a barrier
Example Echo
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Echolocation
Echolocation the process of using reflected
sound waves to find objects
Uses animals such as dolphins, bats, and birds
use this to hunt food and detect objects in their
way
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Echolocation and Bats
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Echolocation Technology
Sonar Sound Navigation And Ranging
Sonar allows navigators on ships detect icebergs
and can help oceanographers map the ocean floor
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Resonance
Resonance occurs when an object vibrating at or
near a natural frequency of a second object
causes the second to vibrate