# 5.2 - Sound

The student will investigate and understand how sound is created and transmitted, and how it is used. Key concepts include

a)  compression waves;

• create a model or diagram of a compression wave  Bloom's Level: Create
• interpret a  model or diagram of a compression wave  Bloom's Level: Analyze

b)  vibration, compression, wavelength, frequency, amplitude;

• use basic terminology of sound to describe what sound is, how it is formed, how it affects matter, and how it travels Bloom's Level:  Apply
• explain the relationship between frequency and pitch   Bloom's Level: Apply/ Analyze
• design an investigation to determine what factors affect the pitch of a vibrating object (includes vibrating strings, rubber bands, beaker/bottles of air and water, tubes, and other common materials. Bloom's Level: Create

c)  the ability of different media (solids, liquids, and gases) to transmit sound; and

• explain why sound waves travel only where there is matter to transmit them  Bloom's Level:  Understand
• compare and contrast sound traveling through a solid with sound traveling through the air. Bloom's Level:  Analyze
• explain how different media (solid, liquid, and gas) will affect the transmission of sound. Bloom's Level:  Understand

d)  uses and applications of sound waves.

• compare and contrast the sound (voice) that humans make and hear to those of other animals (includes  bats, dogs, and whales)  Bloom's Level:  Analyze
• compare and contrast how different kinds of musical instruments make sound (includes string instruments, woodwinds, percussion instruments, and brass instruments)  Bloom's Level: Analyze

### BIG IDEAS

Sound is a form of energy which travels in waves.

### UNDERSTANDING THE STANDARD

• Sound is a form of energy produced and transmitted by vibrating matter.
• Sound waves are compression (longitudinal) waves.
• When compression (longitudinal) waves move through matter (solid, liquid, or a gas), the molecules of the matter move backward and forward in the direction in which the wave is traveling. As sound waves travel, molecules are pressed together in some parts (compression) and in some parts are spread out (rarefaction). A child’s toy in the form of a coil is a good tool to demonstrate a compression (longitudinal) wave.
[img width="283" height="145" src="file://localhost/Users/kirkwood/Library/Caches/TemporaryItems/msoclip/0/clip_image002.png" alt="Sound wave.jpg" v:shapes="Picture_x0020_0">
• The frequency of sound is the number of wavelengths in a given unit of time.
• The wavelength of sound is the distance between two compressions or between two rarefactions. The wavelength can be measured from any point on a wave as long as it is measured to the same point on the next wave.
• When we talk, sound waves travel in air. Sound also travels in liquids and solids. Sound waves must have a medium through which to travel.In a vacuum sound cannot travel because there is no matter for it to move through.
• Pitch is determined by the frequency of a vibrating object. Objects vibrating faster have a higher pitch than objects vibrating slower. A change in frequency of sound waves causes an audible sensation—a difference in pitch.
• Amplitude is the amount of energy in a compression (longitudinal) wave and is related to intensity and volume. For example, when a loud sound is heard, it is because many molecules have been vibrated with much force. A soft sound is made with fewer molecules being vibrated with less force.
• Sound travels more quickly through solids than through liquids and gases because the molecules of a solid are closer together. Sound travels the slowest through gases because the molecules of a gas are farthest apart.
• Some animals make and hear ranges of sound vibrations different from those that humans can make and hear.
• Musical instruments vibrate to produce sound. There are many different types of musical instruments and each instrument causes the vibrations in different ways. The most widely accepted way to classify musical instruments is to classify them by the way in which the sound is produced by the instrument. The four basic classifications are percussion instruments (e.g., drums, cymbals), stringed instruments (e.g., violin, piano, guitar), wind instruments (e.g., flute, clarinet, trumpet, trombone), and electronic instruments (e.g., electronic organ, electric guitar).

### ESSENTIALS

Essential Questions:

·  How does sound travel?

·  How do scientists describe sound?

·  How does sound change when traveling through different states of matter?

·  How does sound affect your life?

·  How do the different ways animals use sound compare to how humans use sound?

·  How would you design a living space that optimizes the use of sound?

In order to meet this standard, it is expected that students will

• use the basic terminology of sound to describe what sound is, how it is formed, how it affects matter, and how it travels.
• create and interpret a model or diagram of a compression wave.
• explain why sound waves travel only where there is matter to transmit them.
• explain the relationship between frequency and pitch.
• design an investigation to determine what factors affect the pitch of a vibrating object. This includes vibrating strings, rubber bands, beakers/bottles of air and water, tubes (as in wind chimes), and other common materials.
• compare and contrast sound traveling through a solid with sound traveling through the air. Explain how different media (solid, liquid, and gas) will affect the transmission of sound.
• compare and contrast the sound (voice) that humans make and hear to those of other animals. This includes bats, dogs, and whales.
• compare and contrast how different kinds of musical instruments make sound. This includes string instruments, woodwinds, percussion instruments, and brass instruments.

### KEY VOCABULARY

absorb - to take in energy

amplitude - the amount of energy in a compression wave; related to volume; lots of molecules are vibrating create a loud sound; fewer molecules vibrating create a soft sound

communication - the imparting or exchange of information

compression - part of a sound wave where the molecules are pressed together

decibel - unit used to measure the degree of loudness

echo - a reflected sound wave

echolocation - locating objects by using echoes; used

by animals such as dolphin and bats.

electronic instruments - electronic organ, electric guitar

energy - the capacity or power to do work; can exist in a

variety of forms: electrical, heat, sound, light are a few

frequency - the number of wavelengths in a given unit of time

matter - anything which has mass and takes up space

media - plural of medium; includes solids, liquids or gases which are necessary for sound to travel; sounds travel fastest through solids because molecules are closely packed together and vibrations are easily transmitted; sounds travel slowest through gases because molecules are farther apart

molecule - the smallest physical unit of an element or compound

percussion instruments - created when a surface vibrates; examples: drums, cymbals

pitch - determined by the frequency of a vibrating object; objects vibrating faster have a higher pitch; slow vibrating objects have a slow pitch; high frequency = high pitch; low frequency = low pitch

rarefaction - part of a sound wave where the molecules are spread out

sonar -  a method for detecting and locating objects submerged in water by echolocation

sound- a form of energy produced and transmitted by vibrating matter.

sound wave  - a compression or longitudinal wave which moves through matter; the molecules of the matter move backward and forward in the direction in which the wave is traveling.

stringed instruments - create sound as strings vibrate; examples: violin, piano, guitar

transmit - to send or forward

ultrasound - sound with a frequency greater than 20,000 Hz; upper limit of hearing

vacuum - a space entirely devoid of matter

vibration - to move back and forth

wavelength - the distance between two compressions or between two rarefactions; can be measured from any point on a wave as long as it is measured to the same point on the next wave

wind instruments -  create sound as air vibrates; examples: flute, clarinet, trumpet, trombone

Updated: May 20, 2016