Most people know that insulation helps to keep your home warm in winter and cool in summer. But did you also know that the right insulation is also highly effective at dampening noise?
Every insulation product has to have what’s known as a Noise Reduction Coefficient, or NRC Value. The NRC measures the build-up of noise within a space and uses a single number index rating to measure how effectively material absorbs sound. NRC ratings range from 0 to 1. This may not actually sound like much of a range, but each point between 0 and 1 represents a percentage. For example, a product with an NRC of 0 doesn’t absorb any sound, while one with a rating of 0.45 absorbs 45% of the sound in the space. Insulation with an NRC of 1 absorbs 100% of the sound.
All buildings have at least some acoustic properties, meaning they will either absorb, reflect or transmit any sound that strikes them. However, just like heat, sound waves always follow the path of least resistance. If there are any leaks or gaps in the acoustic insulation, sound will find them!
How Does It Work?
When a sound wave strikes the insulation, the sound wave causes the fibres of the insulating material to vibrate. This vibration creates heat – albeit in tiny amounts. Sound absorption is thus accomplished by way of energy to heat conversion. The more fibrous the insulating material, the better the absorption of sound.
Frequency also significantly affects how well sound is absorbed. Generally speaking, low-frequency sounds are very difficult to absorb because of their long wavelength. This is not usually a problem for humans, however, because at very low frequencies (less than 250 Hz), the sensitivity of our hearing, and, therefore, perceived loudness, is poor.
For most insulation materials selected for acoustic purposes, the thickness of the material play the greatest role in how well, or not, it absorbs sound. Aerolite’s 135mm insulation has an NRC Value of 1.1, making it ideal for soundproofing applications. Contact us today to find out more.