Sound Do you hear what I hear Created

Sound: Do you hear what I hear? Created by: Jill Mc. Cormick 3 rd Grade Science Unit on Sound

What was sound 1? �A door knock

What was sound 2? �A car starting

What was sound 3? �A Hair Dryer or Blow Dryer

What was sound 4? � Birds chirping

What was sound 5? � Someone typing on a computer keyboard.

What was sound 6? � Dogs barking

What was sound 7? � Water filling a glass

What was sound 8? � Someone clicking a pen

What was sound 9? � Glasses clinking together

What was sound 10? � Frogs croaking

What was sound 11? � Tearing paper

Where does sound come from? � Sound comes from vibrations. � Vibrations are back and forth movements that occur very quickly. � Vibrations can be transferred from one material to another causing that material to vibrate. � Vibrations can travel through: solids, liquids, and gases. � Vibrations cannot travel through empty space.

Materials that sound can travel through best are…. �Solids! ◦ Metal ◦ Wood ◦ Cloth ◦ Plastic

What do molecules look like? � Solid-the molecules are very close together. � Liquid- the molecules have some space between them. � Gas-the molecules have a lot of space between them.

Sounds have different pitch and volume. What is pitch? Pitch-is how high or low it is. Examples of High pitch are: ◦ ◦ Bird chirping Woman’s scream A bell A toy squeaking Examples of Low pitch are: ◦ ◦ A man’s voice A truck’s motor Thunder A Drum

Pitch � There are three ways that the pitch can be changed. � Length � Thickness � Tightness

Length � Length of an object can change the vibration and cause the pitch to change. � Shorter ones. � The materials vibrate faster than longer faster a string, wire, or air in a tube vibrates, the higher the pitch of the sound.

Thickness � Thinner ones. � Thinner can change pitch. strings or wires faster than thicker vibrating materials have a higher pitch than thicker ones when they are vibrated.

Tightness � Tightness of the stretch of the string or wire can change the pitch-the tighter the stretch of the string, the higher the pitch of the sound. � Guitars and pianos have screws that can tighten the wire. � Tightening the wire to tune the instrument can change the pitch. � Tighter higher. wires vibrate faster, making the pitch

Volume What is volume? Volume-is the loudness or softness of a sound. Examples of Loud volume: ◦ ◦ Someone yelling Fireworks A gun firing A tree falling Examples of Soft volume: ◦ ◦ Tapping a desk lightly Whispering to someone Cat meowing A car motor running It takes more force to produce loud sounds than soft sounds.

Volume � There are two ways that volume can be changed: ◦Strengthen of vibrations ◦Distance

Strength of vibration � Vibrations are made stronger or weaker by striking or plucking objects harder or softer, the volume will get louder or softer. � It the force is decreased, the volume becomes softer. � If the force is increased, the volume becomes louder.

Distance � If the sources of the vibrations are farther away, the volume of the sound is softer. � The closer the source of the vibrations, the louder the volume of the sound will be. � Examples ◦ ◦ of objects with volume control: Radio TV CD players Computers

Review Question 1 � Through which substance does sound travel the best? Why? ◦ Solids-because they the molecules are closer together and it can travel faster.

Review Question 2 � What is the speed of the vibrations when you make a high pitched sound? � A. No Vibrations � B. Slow Vibrations � C. Fast Vibrations

Answer to Review Question 2 � What is the speed of the vibrations when you make a high pitched sound? � A. No Vibrations � B. Slow Vibrations � C. Fast Vibrations

Review Question 3 � What is the speed of the vibrations when you make a low pitched sound? � A. No Vibrations � B. Slow Vibrations � C. Fast Vibrations

Answer to Review Question 3 � What is the speed of the vibrations when you make a low pitched sound? � A. No Vibrations � B. Slow Vibrations � C. Fast Vibrations

Review Question 4 � What is the speed of the vibrations when there is no sound? � A. � � No Vibrations B. Slow Vibrations C. Fast Vibrations

Answer to Review Question 4 � What is the speed of the vibrations when there is no sound? � A. � � No Vibrations B. Slow Vibrations C. Fast Vibrations