Our Guide to Room Acoustics page covers an array of information ranging from the causes of poor acoustics to the difference between Soundproofing and Sound absorption. The aim of the page is to give our customers a brief but better understanding of acoustics and demystify some of the more complicated concepts that surround the subject. One of the key principles that is central to what we do and how we do it is ‘Reverberation Time’ (RT).  Below is a short, but useful guide to Reverberation and Reverberation Times. This includes our own guidelines to suggested RT – taking individual room types and giving specific RT parameters that we try and adhere to for all of our projects.

What is Reverberation Time (RT)?
Reverberation time is the most important factor when assessing a room with a noise problem. RT is defined as the time it takes, in seconds, for the sound pressure level from the original sound to drop by 60dB after the sound source has stopped generating the sound. A room with a high RT generally has a problem with noise as sound travels for long distances without being absorbed. Rooms with a high RT almost always have an issue with echo as sound is reflected from hard surface to hard surface. This causes issues with speech intelligibility, particularity for those with any hearing impairment.

Our Guide to Reverberation Times
In the interior acoustics industry, there are surprisingly few guidelines regarding the levels of noise in different room environments. Apart from BB93 regulations, which set out standards for acoustics in schools, there aren’t any other guidelines that deal specifically with reverberation times.  With years’ of experience of working with a plethora of noise problems under our belt, we now work within our own set of RT guidelines which enable us to assess and solve noise problems in a wide range of room types. The Resonics recommendations for RT in different room types are shown below.

Room type

  • Open Plan Office
  • Enclosed Office
  • Meeting Room
  • AV/VC Room
  • Primary School Classroom
  • Secondary Classroom
  • Nursery School Classroom
  • Small Lecture Room
  • Large Lecture Hall
Assembly Hall

Suggested RT

  • <1 Second
  • <0.6 Seconds
  • 0.6-0.8 Seconds
  • <0.5 Seconds
  • <0.6 Seconds
  • <0.8 Seconds
  • <0.6 Seconds
  • <0.8 Seconds
  • <1 Second
0.8 – 1.2 Seconds

Room Type

  • Sports Hall
  • School Corridor/Stairwell
  • Dining Room/Canteen
  • Restaurant
  • Church/Village Hall
  • Library
  • Swimming Pool
  • Call Centre
  • Theatre/Auditorium
Cinema

Suggested RT

  • <1.5 Seconds
  • <1.5 Seconds
  • <1.0 Second
  • <1.0 Second
  • <1.5 Seconds
  • <1.0 Second
  • <2.0 Seconds
  • <0.8 Seconds
  • 1.5-2 Seconds
0.8-1.2 Seconds

Understanding and controlling Reverberation Time is central what we do. For more information about RT and other principle surrounding acoustics, visit our newly launched Acoustics Page.