Sound Isolation – Air Space vs. Mass

When it comes to noise control, both mass and airspace play important roles in reducing sound transmission. Here’s a comparison of how mass and airspace contribute to noise control:


  1. Mass acts as a barrier to sound transmission. Sound waves have difficulty passing through dense and heavy materials.
  2. Increasing the mass of a partition, such as walls or floors, helps to block and absorb sound energy. Heavier materials, such as concrete or mass-loaded vinyl, are commonly used for this purpose.
  3. Mass is particularly effective in reducing low-frequency sounds, which have longer wavelengths and require more energy to transmit.
  4. Adding mass to an existing structure can be challenging and may require modifications to the building’s construction.


  1. Airspace creates a buffer zone that impedes sound transmission. The larger the airspace, the greater the sound isolation.
  2. An airspace acts as a sound trap, preventing direct transmission of sound waves through solid materials.
  3. Airspace can be effective in attenuating mid- to high-frequency sounds, which have shorter wavelengths.
  4. Incorporating airspace can be more feasible during the initial design or renovation phase.

Combining Mass and Airspace:

  1. The most effective noise control strategies often involve a combination of both mass and airspace.
  2. By utilizing both mass and airspace, sound transmission can be addressed across a broader range of frequencies.
  3. A common approach is to have a double-wall construction, where two separate walls with an airspace in between are built. This setup combines the sound-blocking properties of mass with the sound-trapping properties of airspace.
  4. The exact configuration and materials used will depend on the specific noise control requirements and the budget available.

It’s important to note that achieving optimal noise control involves considering other factors as well, such as proper insulation, sealing, and acoustical treatment. Consulting with acoustical engineers or professionals experienced in sound isolation can help determine the best combination of both.