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2 Minute Read

The Resonics Guide to Reverberation Time

Reverberation time (RT) is one of the most important concepts in interior acoustics — and for a good reason.

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Guide

Reverberation time plays a key role in diagnosing and solving noise issues in almost any type of space. Simply put, RT measures how long it takes for sound to drop by 60 decibels after the original sound source has stopped.

Understanding a room’s RT gives us a clear indication of how sound behaves within that space and how much it lingers.

This is crucial when identifying the severity of a noise problem and selecting the right acoustic treatments. Different rooms serve different purposes and each one will require a tailored level of sound absorption to achieve optimal acoustic comfort.

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Rooms with long RTs typically suffer from excessive echo and background noise. In these environments, sound waves reflect off hard surfaces, travelling and overlapping, rather than being absorbed. This results in poor speech intelligibility and low acoustic comfort, making it harder to concentrate, communicate or relax.

Whether it’s a restaurant where conversations become muddled, a classroom where students struggle to hear their teacher or an office filled with distracting echoes, high RT is often the root cause.

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Despite the importance of reverberation time, there is still limited guidance on acceptable levels across different room types.

After years of working in a range of interior spaces, from open-plan offices to auditoriums, we’ve developed our own set of recommended RT ranges. These act as a reliable baseline for achieving acoustic comfort and clarity, ensuring each space is treated appropriately for its intended use.


Room Type Suggested RT
Open Plan Office <1.0 second
Enclosed Office <0.6 seconds
Meeting Room 0.6 – 0.8 seconds
AV/VC Room <0.5 seconds
Primary/Nursery Classroom <0.6 seconds
Secondary School <0.8 seconds
Lecture Hall <1.0 second
Theatre/Auditorium 1.5 – 2.0 seconds
Assembly Hall 0.8 – 1.2 seconds
School Corridor/Stairwell <1.5 seconds
Dining Room/Canteen <1.0 second
Restaurant <1.0 second
Church/Village Hall <1.5 seconds
Library <1.0 second
Swimming Pool <2.0 seconds
Call Centre <0.8 seconds
Cinema 0.8 – 1.2 seconds
Sports Hall <1.5 seconds