As can be seen by the illustration it is important to absorb sound at ceilings and walls, before it spreads even further. The effect reached is a lowering of the reverberation time, making it noticeably quieter and bringing with it a "snowball effect". As the room becomes quieter the people in the room also become quieter as they no longer have to compete with the in-room noise.
 

Conclusion:

The question, do only the sky swallow noise, can clearly be answered with a no. Open-plan offices can be designed to have an optimal acoustic so that noise or high in-room noise levels need no longer be a major problem. The all deciding factor is the early incorporation of acoustics into the planning before creating or constructing an area. The ceiling provides the largest possible area that can- and must be fitted with high absorbing materials. However the wall areas should also be considered in the acoustic calculations. For new buildings the described arrangement of acoustic panels should be strictly adhered to. As for refurbishments the actual situation on-site must be taken into account.

To help planners and users to choose from the wide range of acoustic ceilings and acoustic wall paneling, norms have been established whereby sound absorbing materials are divided into a scale of values. Open-plan and large offices should only be fitted with sound absorbing materials from the absorption class A. These materials consist of a sound absorption value α_w>0,9.

Of interest is that the field of acoustic upgrading allows for various solutions. This is usually possible without losing ceiling height and without adversely effecting the architectural structure. Because the sensitive and very important field of room acoustic is so vast with many snares almost all projects should be assessed by an acoustic expert.Schallabsorptionswert