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
What it is and how to use it.
Investors in People: CIOB achieves gold
Reflecting a commitment to employees and members.
Scratching beneath the surface; a guide to selection.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.
UK gov apprenticeship funding from April 2024
Brief summary the policy paper updated in March.
For the World Autism Awareness Month of April.
70+ experts appointed to public sector fire safety framework
The Fire Safety (FS2) Framework from LHC Procurement.
Project and programme management codes of practice
CIOB publications for built environment professionals.
The ECA Industry Awards 2024 now open !
Recognising the best in the electrotechnical industry.
Sustainable development concepts decade by decade.
The regenerative structural engineer
A call for design that will repair the natural world.
Buildings that mimic the restorative aspects found in nature.
CIAT publishes Principal Designer Competency Framework
For those considering applying for registration as a PD.
BSRIA Building Reg's guidance: The second staircase
An overview focusing on aspects which most affect the building services industry.
Design codes and pattern books
Harmonious proportions and golden sections.
Introducing or next Guest Editor Arun Baybars
Practising architect and design panel review member.