Sound

What do earthquakes, sonograms, music and baby talk have in common? They are all produced by sound waves, which are created when any substance vibrates. Sounds can be used not only for communication, but also for navigating through the ocean or viewing parts of the body for medical diagnosis. Learn about what sound is, how hearing works and the many uses of sound through the direct links on The Times’ Launch Point Web site: https://www.latimes.com/launchpoint/.

Level 1

The Science of Sound: How does sound travel? What transmits sound better, wood or metal? Explore the world of sound through such hands-on experiments as designing reed instruments and making a model eardrum. Learn how composers write music through video and audio clips and view online projects that demonstrate various aspects of sound.

https://www.smm.org/sound/topcss.html

Echo the Bat: How can bats fly and find food when it’s pitch dark? Read an illustrated story that explains how bats can “see” with their ears. By making sounds and listening to echoes, bats can sense their surroundings in a process called echolocation.

https://imagers.gsfc.nasa.gov/intro/story.html

Energy in the Air: Sounds From the Orchestra: Musical tones are produced by air vibrating at a certain rate or frequency. View pictures of sound waves and find out why different instruments in an orchestra produce unique sounds. Learn terms that describe types of sounds and try some fun activities.

https://tqjunior.advanced.org/5116/

Level 2

Sound: Scientists measure the rate of vibrations of a sound in hertz (Hz); a person can hear sounds up to 20,000 Hz while a porpoise can hear sounds up to 150,000 Hz. View diagrams that explain the properties of sound, learn about echoes and recording devices, and enjoy some fun facts about sound.

https://library.advanced.org/26585/

The Art of Foley: Sounds are an important part of making films come alive. Learn how Foley Artists uses items such as coconut shells, frozen romaine lettuce and corn starch to create film sounds such as running horses or snow crunching underfoot.

https://www.marblehead.net/foley/

Sounds of Silence: How does the ear hear? What does it mean to be deaf? View animations of how the ear works, learn about the causes and types of deafness, and discover ways to communicate without sound.

https://library.advanced.org/15390/

Level 3

The Soundry: Sound can be used for navigation, weather forecasting and medical diagnostic tools. Learn about the physics of sound and how our ears work as well as various applications of sound, such as ultrasound and sonar. Trace the history of sound recording inventions beginning with Thomas Edison in 1877 and explore sounds in an interactive lab.

https://library.advanced.org/19537/Main.html

NOVA Online: Sonic Boom Basics: Learn about the speed of sound and how sonic booms are created. Find out what other ways sonic booms can be generated besides airplanes moving at supersonic speeds.

https://www.pbs.org/wgbh/nova/barrier/boom/

Crackling Noise: Advanced Level: Have you ever heard an earthquake? Listen and view simulations of various sounds, including the sound of the Northridge Earthquake speeded up 100 times. Learn how scientists study sound waves to discover how things work.

https://simscience.org/crackling/Advanced/ SnapCracklePop/WhatIsCrackling.html

EXPLORER’S QUEST

The answer to this Internet quiz can be found in the sites at right.

Does sound travel faster through a solid or a gas?

CLUE: See the Soundry

Find What You Need to Know: Have a project on California history? Need help doing a math problem? Launch Point now covers more than 100 topics for getting your schoolwork done. Go to https://www.latimes.com/launchpoint/ for the full list of subjects and direct links to the best Internet sites.

Answer to last week’s Quest: The Dead Sea is seven times saltier than the ocean.

Launch Point is produced by the UC Irvine department of education, which reviews each site for appropriateness and quality. Even so, parents should supervise their children’s use of the Internet. This column was designed by Anna Manring.