1. Sound Vocabulary Terms Objective (2.1):Describe the factors that affect the pitch and loudness of sound produced by vibrating objects. (November 16, 2011 New Vocabulary Review Terms For Friday)

2. Vibrations Definition: The rapid back and forth movement of an object that causes sound. Example: Plucking a ruler on the side of a desk. (model) Example: Strumming the string on a guitar. Example: Beating a hand on a desk.

3. Vocal Cords Definition: Folds of thin muscle tissue in our larynx or voice box. Example: Our vocal cords vibrate when we speak.

4. 2)Energy Definition: The ability to cause change. Example: Sound waves lose energy as they travel. Therefore, sounds that travel over longer distances are more difficult to hear.

5. Definition: Something that can be heard-a form of energy that is transmitted by an object vibrating. Example: Sound waves reflect off of hard surfaces and form echoes. 3)Sound

6. Waves: (definition) A disturbance that carries energy from place to place. Example: Ultraviolet rays are carried to the Earth by waves of energy

7. Medium: The material through which a wave travels. Solids, liquids, and gasses make up the three mediums that sound travels through.

8. Mechanical Waves: Waves that require a medium to travel through. Sound waves travel faster through a solid medium than through water or air.

9. Volume: How loud or soft a sound is The more energy the sound wave has the louder the sound seems. The intensity of a sound is the amount of energy it has. You hear intensity as loudness. The higher the amplitude of the sound wave, the louder the volume; the lower the amplitude of the sound wave, the softer the volume. High Energy/Tall Sound Wave=Loud Volume Low Energy/Short Wave=Soft Volume

10. Frequency: The number of complete sound waves that pass a given point in a certain period of time. High Frequency Sound Waves=5 sound waves pass a given time and point (high pitch sound) Low Frequency Sound Waves=3 sound waves pass a given time and point (low pitch sound) High Frequency Sound Waves

11. Amplitude: The amount of energy in a sound wave. (How loud or soft a sound is) The more energy the sound wave has the louder the sound seems. The intensity of a sound is the amount of energy it has. You hear intensity as loudness. High Energy/Tall Sound Wave=Loud Sound Low Energy/Short Wave=Soft Sound

12. Pitch: How high or low a sound is High Pitch Sound Waves: These sound waves demonstrate high frequency (several sound waves in a time and space) Low Pitch Sound Waves: These sound waves demonstrate low frequency (only a few sound waves in a given time and space) High Frequency Wave

13. Compression Compression: The particles of the medium are pushed together.

14. Rarefaction Rarefaction: The particles of the medium are far apart.

15. Wavelength Wavelength: The distance between two compressions in a sound wave.

16. Echo: A sound wave that reflects off of hard and smooth surfaces. The Sound Waves bounced(reflected) off of the wall during our Bounce Lab and came back to the sound source (kids screaming) like a basketball bounces off of a wall and comes back to the passer.

17. Echolocation Definition: The process of using reflective sound waves to find an object. Example: Bats use echolocation to hunt for food and discover barriers in their way (they bounce sound off of objects and wait to see how long it takes the echo to return-if it’s a quick return, the object is close, if it’s a long return, the object is far away)

18. Ultrasonography Definition: Using echoes to see inside a patient’s body Example: Echoes are converted into images that can be seen on a television monitor

19. Absorb Definition: To take in another substance. Example: Sound waves are absorbed (not reflected) by a bush and we do not hear an echo.

20. Reflect Definition: To bounce off of another object Example: Sound waves bounce off of hard and flat surfaces causing an echo

21. Sonic Boom Definition: The sound made when an object breaks the sound barrier by going faster than the speed of sound (340 m/s at sea level). Example: A plain breaking the sound barrier.

22. Sound Discrimination Definition: Being able to tell the difference between different sounds. Example: Telling the difference between the sound of a train and a plain.

23. Hertz The unit used to measure the frequency of sound waves (pitch). The frequency of a high pitch sound on a piano is about 8,000 (Hz).

24. Decibel Definition: The unit used to measure the loudness (volume and amplitude) of an object. Example: The decibel level of a busy street is about 60-70 dB’s.

25. Rarefaction Definition: The area of low pressure in a sound wave (opposite of compression) Example: See illustration to the right.