Factors affecting sound attenuation
In cavity wall and floor construction the sound attenuation can be increased by
- increasing the mass per unit area of the materials on each side of the wall or floor. The
greater the weight per unit area, the better the sound insulation.
- eliminating all solid connections between each face of the wall or floor
- increasing the cavity depth
- increasing the thickness of the sound-absorbing material in the cavity.
- increasing the distance between studs or joists
- increasing the distance between resilient metal channels
Some of the factors above are more important than others. Some may be insignificant in certain
types of construction. The type of sound-absorbing material sometimes has an effect on the sound
insulation and sometimes it does not. The algorithms take these factors into account and give
predictions of sound ratings for common wall and floor constructions that satisfy the important
If you cannot get an estimate for a particular construction, there are two possible
- The design you are using does not give good sound insulation and so is not considered.
For example, there are no resilient channels and gypsum board is attached directly to wood
- The design parameters exceed those used to develop the regression equations used in this
program. The errors associated with predictions made for such designs would have unknown