This is a snippet from our Acoustical Design in Modern Architecture course. This course is approved for HSW credits nationwide.
Using basic concepts of acoustics, there will always be three basic ways to attenuate or reduce sound.
- If possible, we can replace sources of sound with others that produce less noise. In a similar approach, we can locate sensitive spaces further from generators of noise, to lessen the acoustic impact on them.
- We can block sound from reaching a receiver with heavier, more massive materials and barricades that are less affected by the kinetic energy of sound waves.
- We can interrupt the path from source to a receiver with light and absorbent materials to absorb the energy of sound waves.
Those three basic principles form the foundation for specific design strategies that follow, which apply equally to controlling sound in every building type. (Part II of III | Read Part I)
- Reflect exterior noise with harder and denser exterior surfaces. The more reflective the face, the higher the percentage of sound energy reflected toward the source. Conversely, that results in a lower percentage of energy transmitted through the wall.
- Absorb energy from exterior noise still coming through walls, before it can penetrate the exterior envelope. This requires the use of high STC ratings for materials or assemblies forming that envelope.
- Prevent exterior noise coming through walls, by using two separate walls around the perimeter, not actually attached to one another. There is a lot of expense with this very effective solution, but it may be necessary if very sensitive spaces must abut exterior walls.
- Most exterior walls of modern buildings are well sealed and contain some type of insulation. The good news is that, if an exterior wall will resist the transfer of heat, it will also resist the transfer of sound energy.
- Sensitive spaces can be placed on the interior and the perimeter spaces inside be reserved for less sensitive uses such as mechanical rooms, restrooms, corridors, etc. The walls surrounding more sensitive interior spaces can be highly acoustically absorbent as well, dealing at that point as a barrier to space to space noise transmission.
- Absorb acoustic energy still coming through the roof before it can make it through the exterior envelope. This will require the use of high STC ratings for the materials or assembly of that roof, especially the insulation(s) used in the assembly.
More sound solutions next week!