SOUNDPROOFING IN ACTION

Noise can be a real nuisance in the wrong place but the volume can be turned down using the right shapes and materials.

- SCOTT DUTFIELD

WHETHER IT'S THE INVADING VIBRATIONS OF OUTSIDE TRAFFIC or the cacophony of sounds created by TVs and smartphones, our homes are a hotbed of sound waves. The basic science of sound is simple: when an object vibrates it causes the molecules in the air to collide with one another in a domino effect that creates a wave of sound.

The wave is only heard when our eardrums are hit by the sound wave and our brain interprets the sound.

Our eardrums can only hear sound waves if the vibrations are in a certain frequency range. Anything lower than 20 vibrations per second (20 Hz) and the human ear can't hear it and, similarly, anything over 20 000 vibrations per second (20 KHZ) is too high for the ear to detect.

The size of sound waves, known as amplitude, determines how loud the sound is heard, which typically relates to the force used to create the vibrations.

For example, the harder you hit a nail into a piece of wood the more the nail and wood will vibrate when struck and the louder the sound. Sound waves aren't just airborne vibrations, however.

They are also generated when one object, such as a floor or door, is impacted by another object, such as your foot or hand, causing it to vibrate and transmit sound waves through walls and floors. This effect is known as impact noise.

When sound waves travel through the air inside your home they will eventually hit something and react in several ways. The waves will either bounce off a hard surface, such as a wall, become absorbed by a soft surface, such as a curtain, or travel through it by causing it to vibrate and emit more sound waves on the other side. That is, of course, unless you've installed a series of soundproof panels that cut the sound waves short.