1. Sound Chapter 15

2. What is sound? It is a ______________wave The disturbance that causes it is a __________ The vibrations are transferred through _______________ Pockets of high and low ____________make up the wave Frequency of sound The number of oscillations in _________per second

3. What is sound? Wave length of sound The distance from one ______pressure region to another Speed of sound _____________dependent Medium dependent At room temperature: ____________

4. How do animals detect sound? Air molecules hit the tympanic membrane The membrane vibrates causing three small bones to vibrate The bones then vibrate a fluid in the cochlea Tiny hairs inside the cochlea are vibrated which cause nerve cells to send electrical signals to the brain.

5. Perception of sound Pitch Depends on the __________of the sound Young human hearing spans from __________________________ Frequency range ___________with age

6. Who hears what?

7. Perception of sound Loudness Depends on the ____________of the wave Measured in decibels (dB) Follows a ____________scale

8. The Doppler Effect The result of a moving sound source Sources approaching a detector cause _________frequencies Sources receding from a detector cause __________frequencies is the frequency received by the detector is the frequency produced by the source is the velocity of the detector is the velocity of the source is the velocity of the speed of sound

9. How do instruments create sound? Woodwind Brass Percussion String

10. Interference Results from two waves ______________each other The result of ___________combining or canceling Appears in both transverse and longitudinal waves Constructive interference When two crests or troughs __________ __________the amplitude of the wave Destructive interference When a crest and a trough meet ____________or cancels the amplitude of the wave

11. Resonance The result of a sound wave frequency matching a boundary's natural frequency Every object has a natural frequency Sound waves at this frequency interfere _____________with the object

12. Standing Wave A standing wave is a wave that appears to stay in one place – it does not seem to move through the medium. Node – a point on a standing wave that has no _______________from the rest position. Antinode – a point where a crest or trough occurs _____________between two nodes.

13. Resonance in Air Columns Open tube To produce a standing wave there must be a _____________on either end of the pipe Each standing wave is called a ____________ They are in multiples of __________wavelengths Closed tube To produce a standing wave there must be a _________on one end of the pipe and an ______________on the other Each standing wave is called a harmonic They are in multiples of ___________wavelengths