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A PRIMER FOR ANIMALS & HEARING Sound & Waves Slide 2 Sound is Vibration Slide 3 Vibrations create Waves Slide 4 Characteristics of Waves Slide 5 Slide 6 Slide 7 Slide 8 Frequency in a Sound Wave determines Pitch Slide 9 Slide 10 Describing Waves (rope demonstration) Frequency Amplitude Wavelength Period = the time between the wave crests Slide 11 Describing Sound Frequency = Pitch Amplitude = Volume (how loud it sounds) What is the term for reflected sound? Slide 12 Tuning Forks & Frequency Which tuning fork will have a higher pitch? UNITS Frequency is measured in Hertz Hertz = Cycles per Second, ie. the number of S curves in one second. These Tuning forks create sounds with frequency 256 Hz & 512 Hz. Slide 13 Tuning Forks & Frequency Which tuning fork will have a higher pitch? UNITS Frequency is measured in Hertz Hertz = Cycles per Second, ie. the number of S curves in one second. These Tuning forks create sounds with frequency 256 Hz & 512 Hz. 256 Hz512 Hz Slide 14 Not all Frequencies of Vibration can be Heard Slide 15 Day 2 Materials 4 Stethocopes Tuning forks Ear funnel setup Flour baggie/watch/air baggie Slinky Funnel/milk jug to hold up to the ear Slide 16 Slide 17 Describe this wave in terms of frequency, amplitude and wavelength. Slide 18 Day 2: Movement of Sound Sound Waves Travel through: Gases Liquids Solids Sound does NOT travel through a vacuum. It requires a medium. Slide 19 Air is the medium for this sound wave Slide 20 Compression Wave http://www.acs.psu.edu/drussell/Demos/rad2/mdq.html http://en.wikipedia.org/wiki/File:Onde_compression_impu lsion_1d_30_petit.gifhttp://en.wikipedia.org/wiki/File:Onde_compression_impu lsion_1d_30_petit.gif Slide 21 A Slinky Can be a Hands On model of movement of a Compression Wave Slide 22 If sound is a compression wave, which medium do you think it will move faster through? Slide 23 Sound travels more efficiently through solids than gases. The sound of the ticking watch will be louder through the flour than through the air. Slide 24 Which will be louder? Slide 25 Sound travels more efficiently through liquids than gases Slide 26 Speed of Sound Substancemeters/secmiles/hours vacuum 00 Carbon dioxide 270604 Air 340760 Hydrogen 1,3202.950 Water 1,4703,290 Glass 5,00011,180 Iron 5,12011,450 Slide 27 Direction of Sound The brain interprets direction from which a sound orginates by the difference in time it takes to get to each ear. Slide 28 Amplify Sound If sound is created by vibrations, what is a strategy for making a sound louder? Slide 29 Slide 30 Slide 31