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Acoustics Testing

Sound insulation testing


Danny McCaul
t: +44 (0)161 295 4615

What is sound insulation?

Sound insulation is a measure of the sound stopped by a barrier such as a partition wall. We can measure the sound reduction index in our transmission suite. This consists of two adjacent reverberant rooms, the difference between the level of the sound in the source room and the receiver room is measured, and the properties of the receiver room are taken into account by calculation.

What is expected of you?

Drawings and written descriptions of the samples must be provided prior to testing (preferably prior to quotation); a test report cannot be provided without this information. We expect that your company will build the wall for testing to ensure the wall is constructed in the usual manner. Providing  all the usual building materials for construction and organising and paying for all transportation costs for these materials as required. The specimen should be constructed using the highest quality of components and labour. The smallest of leaks can greatly reduce the measured sound insulation index.


What do the results look like?

The results will be presented as part of a complete report. A single figure weighted reduction value (RW) will be calculated, with appropriate C and Ctr weightings. The reduction values (R) for each 1/3rd octave value will also be calculated. These results will be presented in a manner accordant with  BS EN ISO 717-1; a specimen results sheet is available. Please note the results are not pass/fail criterion.

What size of sample should I provide?

sound insulation aperture size
sound insulation aperture size

The aperture size is 2.4m x 3.6m and you should expect to fill this for the test.

What height is the aperture off the floor?

The aperture begins at a height of 400mm from the floor.

Who installs?

We recommend that your company provides the building materials for construction and installs the wall for testing.

Can the aperture size be reduced for testing small objects?

If you are testing a smaller object such as a window a wall must be constructed. You will be charged for this and the work to reduce the aperture size will be subcontracted to a team of highly skilled builders, who are familiar with construction work for acoustic testing.

Are the results obtained in the lab representative of what you would expect the wall to achieve on site?

As a rule of thumb it is expected that the results achieved in the lab will be 5dB higher than can be expected on site. This is due to a variety of reasons; including flanking transmission, rebuild quality on site etc.

Labour – can the university carry out the build?

We can subcontract the work to reduce the aperture size to a team of highly skilled builders, used to building work for acoustic testing.

What do our customers most often forget when preparing for testing at the laboratory?

We can get by on the day with most forgotten things but would advise that you bring plenty of sealant!

How long is each test?

The longest part of each test is always the build process. When it comes to the acoustic tests the first sound insulation test is the longest because we need to measure the reverberation times in the receiver room, after this provided the material of the partition wall doesn’t change subsequent  sound insulation tests are shorter. After calibration the first test will take 1hour to 1½ hours and subsequent tests which don’t need reverberation times should take 30 mins each.

How many tests can I do in a day?

Provided the construction process doesn’t hold us up to much we can do up to four sound insulation tests in a day. If necessary we can do more than this for an additional charge.

When will I get the report? When can I get the results?

We can provide preliminary results on the day of test. The test report will follow in 2-4 weeks after test completion, depending on our workload and the complexity of the test carried out.