Many people are confused by the term “acoustic ceilings” and it’s hardly surprising due to the fact all suspended ceiling manufacturers claim their ceiling tiles have acoustic properties.
Obviously manufacturers make these claims because they know it’ll sell more tiles, and technically they are all correct in claiming their tiles are acoustic, but the truth is there are two types of acoustics they are referring to, and they are at complete opposite ends of the spectrum.
The two types of ceiling tile acoustics are sound absorbers and sound reflectors, and both these types are useful in different applications.
As the title suggests these help absorb the sound which are very useful at preventing echo (reverberation) in rooms, especially corridors or large halls. Some tiles are better than others and the better they are at absorbing sound the higher the NRC (Noise Reduction Coefficient) value will be (NRC value of 1.0 being high and a NRC value of 0.1 being low).
Obviously these reflect sound and are very useful in certain circumstances. For example if you had a room with a noisy machine inside and you wanted to stop some of the noise penetrating out of that room and disturbing others, you could install tiles which are good at reflecting sound. This would help keep the noise contained within the room.
Decibel Rating (dB)
Tiles which are good absorbers tend to have a low dB (decibel) rating, hence most manufacturers do not state the dB rating of these tiles, and stick to offering you their NRC rating. Likewise the opposite is true for low NRC rated ceiling tiles, the manufacturers will show their dB rating instead.
The problem is most people have heard of dB (decibels), and know this has something to do with sound and then immediately jump to the conclusion that a higher dB rated ceiling tile is what they require, and yet in the majority of cases they would have been better off with a high sound absorbing ceiling tile.
Some of the best sound absorbing ceiling tiles are made from glass fibre or rock fibre. Sound reflecting ceiling tiles tend to be made from harder materials like calcium silicate, gyproc or some types of mineral fibre.
If you require further information regarding ceiling acoustics then we would suggest contacting a ceiling contractor who has experience with acoustics.
Alternatively Ecophon are probably one of the best manufacturers to speak to regarding acoustic ceiling tiles.