Reverberation is echo. Sound reflecting off the surfaces within a room. It can make understanding speech very difficult, meetings impossible, time in a restaurant stressful instead of relaxing. And yet there has been a lot of research into creating the ideal reverberation time within a room. It’s possible to design the internal acoustic conditions within a room to enhance the listening experience whether it’s a meeting room, music venue, multi media suite or community hall.
Calculation of reverberation times using recognised formulae such as Sabine or Eyring are a useful baseline for room designers and we’re happy to perform them, but they do have limitations, so wherever possible we recommend measurement. A reverberation time survey gives an accurate picture of the acoustic condition of the existing room and allows us to recommend a level of treatment following the class A to E system in line with ISO 11654 to match the internal acoustic condition to the intended purpose of the space.
We do this by introducing absorption into the room. Absorption in acoustics is the changing of sound energy into heat. In layman’s terms when a sound wave hits the boundary wall of a room some of its energy will be reflected back into the room (reverberation) some of it will pass through the boundary (sound insulation – or lack of it) and some of it will be “absorbed” i.e. converted into heat. Some surfaces and materials absorb sound energy better than others. We use proven materials and the absorption process to control how much energy is reflected back into the room. The ISO 11654 classification system is a way of identifying the acoustic absorption properties of materials. This gives designers great flexibility in how the space can be treated.