Acoustics

The decibel scale measures sound based on human hearing, which makes it one of the most unusual scientific measurements. How are decibel calculated and what do they tell us about sound?

By Sascha Bos

When an airplane flies faster than the speed of sound, you hear a large booming sound. But how can something that seems so simple cause such a boom?

By Austin Henderson

Radar is used to track storms, planes, and weapons and also to create topographic maps. Learn about radar, radar technology and Doppler shift.

By Marshall Brain

I was watching an old movie today, and two kids (neighbors) were talking to each other using two tin cans and a string. Does that really work? If so, why does it work?

What makes sound a weapon? Review the basics of sound and discover exactly how the LRAD produces its "beam of sound." We'll also explore LRAD's hailing and warning abilities and other uses for sound.

By Tracy V. Wilson

Overtone is a sound accompanying the main tone produced by a vibrating body. The number and loudness of overtones determine the timbre, or tone color, of a musical sound.

An object free to vibrate tends to do so at a specific rate called the object's natural, or resonant, frequency.

When sound waves strike the ear, these waves produce the sensation of sound. Let's take a look at how sound waves work.

Do you remember holding a large conch shell up to your ear to hear the ocean? Why does this work even when you're far away from the sea?

The idea that something so intangible as acoustic levitation can lift objects may seem unbelievable, but it's a real phenomenon.

By Tracy V. Wilson

If you have trouble sleeping you might have been told to get a white noise machine. But white isn't the only color of noise out there.

By Talon Homer & Austin Henderson

Did you ever wonder how to measure how fast sound travels in the air? Read this article to learn how to measure sound travel in the air.

By HowStuffWorks.com Contributors

What is white noise? There's a little more to it than the ambient noise you associate with a humming air conditioner or whirring fan.

By Nicole Antonio

You know that sound synonymous with a certain laser blaster from a galaxy far, far away? Yeah. It sounds like that.

By Mark Mancini

A sound wave alone probably won't kill you. Crank the volume on a terrible song, though, and you just might annoy everyone to death.

By Oisin Curran

There are so many things in this world that are possible, and shattering glass with sonic force is one of them - but just how probable is it, really?

By Christine Venzon

Pianos lose their tuning, guitars fall out of key -- even church organs need to be tuned every now and then. For centuries, the only sure-fire way to tell if an instrument was in tune was to use a tuning fork.

By Tristin Hopper