Sound reduction index (SRI)
The sound reduction index (SRI) is a measure of the reduction in the intensity of sound when it passes through part of a building; in other words, the level of sound insulation provided. It is the difference between the sound intensity that hits one side of an object (such as a wall, door, window, partition and so on) and the sound intensity measured on the other side, expressed in decibels (dB).
When sound hits the surface of a material, some will be reflected, some will be absorbed by the material and some will be transmitted through it. By determining the SRI, the effectiveness of the element as an insulator (the amount of sound that it has prevented from passing from one side to another) can be assessed.
SRI is defined in the series of international standards ISO 16283 (parts 1-3). Standard testing methods, both in laboratory and field environments, have been established for measuring SRI.
In the USA, the sound transmission class rating is typically measured as the Noise Reduction Coeffiecient (NRC). This measurement is in the process of transitioning to the Sound Absorption Average (SAA).
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Cross-ventilation in buildings. Do you have it ?
Will you need it ? after June 15 and the new Part O ?
Share your knowledge with the industry.
Create an account and write the first of many articles.
The green jobs delivery group.
CIAT commentary after the first meeting.
Liverpool's world heritage site status
Who is to blame?
Research recommends focussing on portfolio success rather than project success.
ICE and BSI launch revised PAS 128 standard.
The revised standard for mapping underground utilities.
Launching the UK net zero carbon buildings standard.
Cross-industry steering group seeks support in delivery.
How to write an inspection and test plan.
Help us update process pieces from your field.
APM report explores existing practice.
Previous reflections on mental health with CIAT.
COVID-19 and the importance of mental wellbeing.
IHBC accreditation recognised by CSCS
As Professionally Qualified Person (PQP).
The Queens speech; bill by bill for 2022.
In order of relevance and with industry responses.
Mental Health awareness week, May 9-15.
Raising awareness of the impacts of loneliness.
Rapidly renewable materials and construction.
The list is growing, and in more ways than one.
Personal experiences of infrastructure maintenance issues.
We shouldn’t build new, If we can’t maintain what's built.
Mass timber: challenges and potential solutions.
Timber Accelerator Hub phase 1 report