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The Nature of Sound. Physical Science Ms. Pollock 2009 - 2010. Sound. http://www.privateline.com/TelephoneHistory/speech.jpg. All sounds produced by an object that vibrates Vocal cords loudspeakers. Sound Waves. Vibration causes air molecules to collide, transferring energy.
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The Nature of Sound Physical Science Ms. Pollock 2009 - 2010
Sound • http://www.privateline.com/TelephoneHistory/speech.jpg • All sounds produced by an object that vibrates • Vocal cords • loudspeakers
Sound Waves • Vibration causes air molecules to collide, transferring energy. • Collisions continue, transferring energy – sound wave • Compressional waves • Compressions • rarefactions
Sound Waves • http://media-2.web.britannica.com/eb-media/20/4320-004-CFE3C8FE.gif
The Speed of Sound • Sound capable of traveling through all types of matter • Cannot travel through empty space • Faster through liquids and solids due to close particle spacing • 347 m/s through air • 1498 m/s through water • 4877 m/s through aluminum
The Speed of Sound • Speed not dependent on loudness • Closer particles = faster transfer of energy • Speed dependent on temperature of medium • Higher temperature = greater speed • Particles colliding faster and more often
Human Hearing • Despite variations in sound, human ear capable of translating • Ears and brain working together to make sense of speech • Ear gathers compressional waves • Ear amplifies compressional waves • Amplified waves travel down nerve impulses to brain • Brain decodes and interprets nerve impulses
Human Hearing • http://www.hearingcare.com.au/hc/images/ear_diagram.jpg
Gathering Sound Waves – The Outer Ear • Visible part of ear, ear canal, eardrum • Visible captures waves and directs • Ear canal passageway to eardrum • Eardrum tough membrane that vibrates • http://www.sinuscarecenter.com/aao/images/39359796.jpg
Amplifying Sound Waves – The Middle Ear • http://www.worsleyschool.net/science/files/ear/ear2.gif • Hammer, anvil, stirrup • Multiply force and pressure produced by sound wave
Converting Sound Waves – The Inner Ear • http://www.hearingcarecenter.com/images/ear.gif • Cochlea and tiny hair cells • Nerve impulses converted by cochlea sent through auditory nerve to brain • Usually location of damage when hearing loss is involved