Sound Testing

What is Sound Testing?

Sound Testing is the generic name applied to a group of acoustic tests that can be carried out to better understand how Sound / Noise moves through materials or constructions such as houses, buildings, workplaces and so on.

Sound Testing is often used to either support an acoustic specification or to demonstrate compliance with specific Building Regulations and/or Standards. When a new construction, or the conversion of an existing building results in two adjoining dwellings being separated by a partition (Party Wall/floor), it is a Building Regulations Part E requirement for this partition to be tested in terms of its sound insulation performance.

The rooms to be tested will be Living Rooms, Bedrooms, dining rooms etc. Kitchens and Bathrooms are not normally tested, but can be relevant in specific open plan situations. Normally the larger room will house the Sound Source and the smaller room, the Receiver. Sound Tests may take the form of an Airborne test, an Impact test or both depending on whether the acoustic properties of Walls, Floors or Ceilings are required to be proven.

What is Sound Insulation Testing for Part E?

This is normally required to demonstrate compliance to Part E of the Building Regulations for England and Wales, and Building Standards in Scotland. This requires sound testing to be carried out in all new-build dwellings and conversions including the criteria for Change of Use, that create two adjoining dwellings with either separating walls, floors or ceilings.

Testing Requirements for: Building Regulations 2000 Approved Document E 2003

Airborne Values (DnT,W + Ctr dB) represent the weighted, standardised level difference between a source room and receiver room. In other words how much the partition reduces sound heard in the receiving room by. (DnT,W) with an added correction term (Ctr), which characterises the level difference with respect to external or ambient noise.

Regarding the airborne result, the higher the dB reading, the higher the acoustic attenuation and therefore the better the performance.

Approved Document E 2003 states that in a new build, the party element must achieve an Airborne Sound Insulation result of at least 45dB and a conversion must achieve a result of at least 43dB.

Impact Values (L’nT,W) are given as the weighted, standardised impact sound pressure level. In other words, how much impact noise is transmitted through to the receiving room.

Regarding the impact result, the lower it is, the more of an effect the party element is having, and the better the sound insulation performance.

Approved Document E 2003 states that a new build must have an impact sound insulation result of no more than 62dB, while the result for a conversion must be no more than 64dB.

For Airborne Tests

A powerful Dodecahedral Speaker that sends sound in all directions, generates high levels of sound using Pink Noise, with balanced frequencies. This level is then measured in multiple locations within the same “Source” room.

The same level of generated noise is maintained but measured in the adjacent receiving room. This then indicates the level of Sound Insulation that the wall or floor offer. There are a range of corrections and calculations such as background levels, reverberation time and so on to get to this number, but it will boil down to a single average dB number used as the key indication that the partition reduces airborne sound by. Typical numbers range from 30dB to 70dB. The higher the number the better as this means that more sound energy is being stopped by the partition. A PASS would be 43dB for a Change of Use or 45dB for a New Build.

For Impact Tests

This involves use of a specialist Tapping machine that creates a series of very loud impacts via a set of engineered pistons being accurately and repeatedly lifted and dropped onto the floor surface to replicate Footfall.

The tapping machine is placed in the upper room and the resultant noise received in the room below is measured. Measurements are taken with the tapping machine in at least four different positions and at least six measurements are taken. This gives six results which are then used along with the reverb and background noise within the source room. Measurements are taken in the receiver room, in third octave bands from 100Hz to 3150Hz. Using all this data, the impact sound pressure level is calculated, giving the floor an impact sound insulation rating. Typical numbers range from 80dB to 40dB. The lower the number the better here as this is a measure of how much sound energy is passed through the floor. A PASS would be 64dB for a conversion and 62dB for a new build.

How many tests are needed?

Depending on the configuration and the quantities of rooms/dwellings, the Sound test will be designed in advance to ensure the right type and quantity of tests are carried out. The amount of separating walls and floors that are tested in your development depends on the quantity & type of dwellings, as well as the method of construction of each partition. If the method of construction of each separating partition is similar and there is under 10 dwellings, 1 standard set of sound tests comprises of two Airborne Wall Tests, two Airborne Floor Tests and two Impact Floor Tests.

Is my construction project ready for testing?

It is imperative that the building is complete to be able to achieve the highest performance. There are times when we have attempted to complete a sound test and the client has not yet had doors fitted. These projects normally fail.

To ensure the best result is achieved following your investment, the following criteria should be followed

• Walls, floors and ceilings must be completed
• Windows & external doors must be fully fitted, glazed and closed
• There should be no radios, fire alarms or other noise generating equipment or plant operating.
•  Any ventilation systems should be installed and closed
• Internal doors should be hung and closed.
• Skirting boards, electrical sockets and light switches should be fitted.
• Generators should not be operating.
• To test Impact sound transmission, we can only test the fabric of the building, therefore there must be no additional final finish floorings fitted
• Rooms in which testing is to be carried out should be empty and tidy with safe access.
• No-one else should be working in the building during the test
• Free access to the properties on both sides of the separating partition is required
• 240v (50Hz) mains power is required within the property to run our test equipment

How much does sound testing cost?

Our sound testing fees offer excellent value for money and quality of service that is split down into the following two considerations

• Site Fee – This varies dependent on location and covers the engineer, equipment and reporting.
• Test Fee - Each test is charged separately to minimise your expenses.

What happens if my sound test fails?

Please remember, if the property fails, we only charge a ‘site fee’ for the re-test PLUS we offer FREE design advice. In the relatively rare event of your test failing, one of our experienced acoustic consultants will review the construction and provide advice on cost-effective solutions to achieve the appropriate standard. Remedial works can be expensive, so it is best to get the job right first time.

Do iKoustic do the tests themselves?

iKoustic partner with leading nationwide UKAS Accredited Sound Testing Specialists to bring a one stop solution to you.

Whilst it is imperative in terms of professional integrity that the two parties remain completely neutral and independent, there are great synergistic opportunities in terms of product specification and proven system performance data that can be shared when planning an acoustic specification.

Contact iKoustic early on in your project to identify the specific requirements and to ensure the best possible chance of passing FIRST TIME. We can also provide impressive savings for bulk-testing and returning customers.