Page 67 - Science Course 3 (Book 2)
P. 67
Mo10-L3a: What are the Properties of Sound Waves?
Key Concept The unit used to measure sound intensity or loud-
ness is the decibel (dB).
What are the Properties of Sound Waves?
Each increase of 10dB results in a sound seeming
What are some properties of sound waves? twice as loud.
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100 Danger zone: Can result in
permanent hearing loss
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40 vacuum cleaner
30 alarm clock, city traf c lawn mower, power tools MP3 player, full volume
20 normal conversation garbage truck
10 whisper library of ce snowmobile
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Moderate Very Loud Extremely Loud
Hearing and the Ear
The part of the human ear that you can see, called
The farther you move from the source,the less the outer ear, collects sound waves.
energy is present in the same area of space.
The middle ear includes the eardrum and three tiny
Loudness is your ear’s perception of intensity. bones called the hammer, the anvil, and the stirrup.
The middle ear amplif es the intensity of sound
waves.
The inner ear contains the cochlea, which changes
the sound waves to nerve signals that the brain can
interpret.
1 meter
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