Sound Attenuation dB

Sound Attenuation refers to the way ceiling tiles insulate sound and stop it travelling through the area in question. The amount of sound that is prevented from travelling from room to room is measured in decibels (dB) and, as a general rule for a reasonable degree of privacy, the minimum sound insulation value between adjoining rooms should be 34dB.

For spaces such as meeting rooms, waiting rooms and classrooms it is important that sound does not travel out of the room. Not only can this distract other people in the vicinity, it can potentially breach confidentiality. Although plasterboard walls stop sound escaping to a certain extent, if the ceiling is not sound insulating, then the noise will escape over the walls and into the adjoining rooms.

If your workplace features suspended ceilings, and you currently have an issue with sound attenuation, the most effective way of reducing room to room transfer of sound would be to replace your existing system with acoustically rated ceiling tiles.

Sound Absorption Class

While Sound Attenuation refers to sound insulating properties, Sound Absorptions Class refers to the ability of ceiling tiles to absorb soundwaves. If no sound absorption measures are taken, sound will be reflected off of surfaces back into the room, much like light. Softer materials will absorb some of this energy, which will help prevent an echoey environment and maintain sound clarity.

There are numerous solutions to the problem of sound reverberation. Often a combination of several tools are implemented, which can include rafts, wall panels, carpets and even free standing structures. However, research suggests that ceilings have the biggest impact on the acoustic quality of open plan offices.

Ceiling tiles vary greatly in their acoustic absorption performance. Acoustic tiles often feature perforations, which are small penetrations in the tile surface. These increase the surface area of the tile, therefore increasing its ability to absorb sound. Perforations range from tiny pinholes to surface fissures that are visible to the eye.

Each tile has a rating to demonstrate how good a sound absorber it is, measured in alpha waves. This rating is between 0.0 (no sound absorption) and 1.0 (100% sound absorption). For ease of comparison, manufacturers tend to categorise tiles into 5 classes. These classes are denoted by letters ranging from ‘A’ (best sound absorbers) to ‘E’ (poorest sound absorbers).