WALLS & CEILING
The most significant conduits of sound between you and the outside environment are your walls and ceilings. To soundproof them, you would need to increase their density. Unlike the brick walls of the past, modern walls are built with other components such as structural elements, insulation, and drywall or plasterboard. Soundproofing a space involves increasing the density of the insulation in the wall.
A common wall insulation material is mineral wool. Also known as rock wool, mineral wool is fireresistant and necessary for the heat insulation of the home. Added within the wall, it reduces sound penetration by three to five decibels. (Generally, the volume of heavy traffic is about 85 decibels, while a normal conversation measures about 60 decibels.) Unfortunately, mineral wool tends to degenerate over time as it is made of a natural material.
An alternative to mineral wool is polyurethane foam. Amos Tadete, product consultant at JD Acoustic, recommends Vicycle from US company Vicoustic. Vicycle is made from recycled polyurethane foam and varies in thickness from three to six centimetres. It can be used for both heat insulation and the reduction of airborne noise. In comparison to mineral wool, Vicycle can reduce sound penetration by up to six decibels and will not degenerate.
While Vicycle is more commonly used in the construction phase of a home, you can soundproof an existing wall too. Another Vicoustic offering, the ISO Blanket, reduces sound penetration by up to 17 decibels. At four centimetres in thickness, it can be added over your wall with existing rock wool or Vicycle without adding too much bulk. Vicoustic products are available at JD Acoustic.
Selina Tay, founder and principal designer at Collective Designs, recommends building a false ceiling with insulation on the inside to keep noise from upstairs filtering downwards.