Why is a highly absorbent ceiling useful in most cases?
In Hochparterre's special issue "Raum hören" (Hearing Space), renowned acoustician Clemens Kuhn-Rahloff gives an interview on good room acoustics and the new SIA standard (click here for the article). On page 7, there is a statement that sticks in the mind:
"...three classic measures that are useful in most cases..."
"... there are three classic measures that are useful in most cases: a background noise, partition walls, and a highly absorbent ceiling."
Why are these three measures effective?
A low background noise makes speech less intelligible at a certain distance. Unconscious eavesdropping decreases—which is precisely what often causes distraction in offices and open-plan areas.
Partition walls interrupt the direct propagation of sound. However, this only works in combination with a highly absorbent ceiling. If the ceiling remains hard (plaster, concrete, etc.), it carries the sound over long distances and the partition walls are only effective to a limited extent in terms of acoustics.
What makes a highly absorbent ceiling so effective?
Above all, their surface area and position. The ceiling surface area is large in relation to the room volume, thus providing a significant absorption surface. In addition, the ceiling is located where a large part of the sound energy arrives and would otherwise be distributed throughout the room. Its influence on intelligibility is correspondingly strong.
This makes it clear that a highly absorbent ceiling lays the foundation for intelligibility in the room.
This suggests that a highly absorbent ceiling is the obvious solution for complying with the new SIA standard 181/1 for room acoustics.
And: It is worth planning for highly absorbent ceilings right from the start. Partitions and background noise can be added later depending on the situation.
Finally, a brief advertisement on our own behalf: Highly absorbent ceilings are our specialty. We use seamless, spray-applied cellulose. This allows for complete creative freedom and can be implemented quickly. Depending on the room and the desired effect, we select different surfaces—from coarse to fine flakes. Our products are also sustainable, free of harmful substances, and flame-retardant.
The Hochparterre special issue "Hearing Space" can be ordered free of charge as a print edition or read as an e-paper.
Jonathan Möller
As someone who is almost deaf, the author knows how crucial room acoustics are for a good room and for good conversations.