Sound Travels: Acoustic Treatment in Offices

Acoustical comfort in the office not only pertains to the specific materials used to mitigate the physical sound but also the ability of a workspace to conduct concentrative, interactive and confidential work. Such cases would be to find the equilibrium with finding solitude to support the knowledge complexity of the work involved and the planned or spontaneous interactions induced for the development of team camaraderie. Also, confidentiality needed for certain work processes encourages the speech privacy achieved from an optimal office acoustic treatment.

The first line of defense for sound mitigation belongs to the architectural process- sound absorption. More than the closed workspaces, the open ones require the acoustical treatment on peculiar parts of the spaces such as floors, walls, ceilings and window coverings to conduct sound absorption. The higher the rate of the material absorption and its acoustical performance, the more comfortable acoustically the open space environment will be. Two key factors that contribute to the sound absorption include the ceilings and floor. High quality ceiling material such as the hanging "clouds" is the most significant contributor in the sound absorption as well as dampening of footfalls contributed by the floors covered with carpet. Floor coverings that are inducing sound absorption include not only carpet, but also cork and linoleum. Materials that are to be avoided and are producing irritating sound of footfalls would include marble and ceramic tile. Additionally, acoustic material of walls can also be applied directly to a surface or integral with the wall finish, such as the acoustic plasters.

If the first technique failed, mechanical means such as the blocking of sound transmission in spaces is incorporated. Sound travels from the noise source to the receiver, so sound barriers are placed to block the noisy paths. Simplest acoustic strategy for sound blocking would include the allocation of noise-generating sources into an enclosed, contained room such as a conference room. The inverse approach which is also a useful reverse strategy would be to locate the noisy areas out in the open while the solitude-inducing activities are to be contained inside the four walls. Separation of the interactive, open work areas and the active circulation corridors from the "heads-down" break areas are achieved through wall placement and zoning strategies. In this case, Sound Transmission Coefficient (STC) can be applied. Example of a sophisticated solution requiring the expertise of engineering acoustics would be the design of hanging panel for sound interruption alongside with sprinkler and fire systems.

Seemingly counterintuitive, a low-level background noise is not desired for a contemporary open workspace to be deemed acoustically comfortable. In fact, this stirs a greater distraction than if higher level of background noise or "white noise" is achieved through the use of tabletop fountains or in-plenum electronic masking systems. Also, minimal HVAC background and provision of masking is necessary to make the background noise uniform.

What other acoustical treatment strategies have you applied for the design of your contemporary office spaces? Share yours by commenting below!