The Science of Sound Waves


What is a sound wave, anyway?

Sound is an essential part of the human experience, helping shape every experience and memory we have. Have you ever wondered though, how sound actually works?

What are Sound Waves

It is a longitudinal, mechanical wave of pressure that expands outwards in all directions from its source, riding along the molecules in the air, much like waves on the ocean. A great way to see this in action is to drop something into a body of water. The circular ripples spread out in all directions, at the same rate of speed. Sound works in the same way. Sound waves oscillate along the medium from atom to atom, losing small amounts of energy each time. This is why volume decreases the further away you move from the source.

Sound requires a medium to pass through. Whether it’s through the air, water, ground, or anything else, sound needs something in order to travel any distance. There are extremely few molecules in the vacuum of space, and as a result sound is unable to travel through it. Hence the saying: In space, no one can here you scream.

Light and heat waves may sound similar, but they work very differently in comparison to sound. They are electromagnetic transverse waves that do not need a medium to travel along. They move through the vacuum of space unobstructed, whereas sound cannot.

A pressure wave is required for sound to exist, and as a result it is affected by the density of the material it is passing through. Sound travels faster as the density of the medium in increased. For example; the speed of sound traveling through air is 344 meters/second, whereas the speed of sound traveling through iron is over 5000 meters/second! The phenomenon is also what causes your voice to sound muffled underwater, or high pitched if you breathe in Helium.

Soundproofing Sound Waves

Not all materials transmit sound well, however. These materials do not transfer vibrations easily, making it difficult for sound waves to pass through them. This is the very principle that we at Residential Acoustics utilize in our AcousticCurtain™, Acoustidoor™, and Acoustitrac™ soundproof curtain products. Our sound proofing material isolates these vibrations, disrupting sound transmission and dramatically reducing volume by up to 30 decibels.

By designing our soundproofing curtains with soundproofing mass-loaded layers and integrating dampening materials, we’ve created soundproof curtains capable of blocking 25-30 decibels of noise, including that annoying low-frequency noise that many apartment renters deal with!

Sound is one of the most amazing aspects of our lives. It allows us to communicate with a friend over the phone, to enjoy classical music, or tell our families and friends how much we love them. It enriches us every day, and helps make life memorable. Sometimes, though, excess sound is not appreciated. No one likes being kept up all night by loud music, or woken in the morning by the sound of traffic! That’s where we come in. With our patented design and commitment to quality, our products can be tailor-made to suit almost any window or doorway, and help restore your peace of mind.

More information on the Science of Sound Waves

If you would like a more detailed and visual explanation on how sound works, please check out the University of Salford’s excellent learning resources on sound waves: University of Salford Acoustics

Also, be sure to check out our AcousticCurtains™ and Acoustidoors™ for great ways to block sound, light, and heat transmission in your home or office!


Written By: Patrick McHugh
Residential Acoustics

One thought on “The Science of Sound Waves

  1. Amanda Ho says:

    My daughter recently moved to a new home which has the HVAC system inside her bedroom. The builder wrapped the equipment meticulously with sound proof materials and installed a louver door to minimize the unbearable noise. His efforts did not pay off; I then tried acoustic curtain as a last resort. The staff knew that I had to have the product within a week; I paid ground shipping and received the custom-sized product on the fifth morning. I am very pleased that the curtain further reduces the noise level and I truly appreciate their professional assistance.

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