Acoustic Testing products process and performance
"These walls are paper thin" is a familiar complaint voiced by apartment residents, hospital patients and office workers, to name but a few, the world over. All too often, however, it is not actually the walls that are the problem but other construction products that make up the different elements of a building - particularly doorsets, windows, glazing systems and seals - that have high rates of sound transmission.
Factors affecting acoustic performance
Multiple factors can impact the acoustic performance of a product. Poor installation, such as gaps between the wall and product, will cause noise leakage.
Similarly, seals and thresholds should be checked for breaks and suitability for the application. Using a suitable seal for the application will result in increased sound insulation. Conversely, a gap in the seal or threshold with the bottom of the door will reduce the ability for noise control.
Finally, architectural ironmongery should always be checked along with the door or window itself. Door or window furniture, such as letterboxes, handles, and locks must be correctly installed to ensure maximum sound insulation.
The standards bodies have responded, and as a result, building regulations and product certification schemes across the world are increasingly incorporating an acoustic rating of products to give a building's users the level of comfort required to live, work and sleep.
These standards have been incorporated into building regulations in many countries, such as the Building Regulations 2010 Part E, which dictates the UK's noise control rules and limits.
Accurate information on acoustic performance is vital for architects, building specifiers, and contractors so that building regulations are adhered to, ensuring the right product for the required application is selected – but obtaining this accurate information requires a specialist acoustic testing process.
What is the acoustic testing process in a laboratory?
Acoustic testing in a laboratory is conducted to demonstrate sound insulation performance to specific acoustic testing standards, which vary according to whether you require the British, European, American or International standards. The advantage of laboratory-based testing for acoustic products is an expertly controlled environment in which to replicate and assess how a product will perform under controlled conditions.
The process may vary somewhat depending on the product being acoustically tested and the standards which they must satisfy.
For example, the acoustic performance of a door assembly is determined by subjecting a representative door assembly to a laboratory BS EN ISO 10140 series of acoustic test standards (the BSI standard that dictates the laboratory measurement of sound insulation in building elements) and in accordance with ISO 717-1.
The laboratory acoustic testing process for a door assembly has four key elements:
1. A test door is installed into a dividing wall that separates two reverberant rooms known as the source room and the receive room
2. Testers take an initial measurement of room volumes (both source and receive rooms) and specimen area, as well as background and reverberation readings within the receiving room
3. During laboratory-based acoustic testing, measurements are taken using pink noise, which is generated in the source room (circa 90–100 dB)
4. Testers then take measurements from within the source room and receive rooms using highly calibrated microphones. A result is then calculated based on all the readings taken
An acoustician or architect may require a doorset or window that will form an integral piece of a parting wall to reach a specific dB to satisfy the relevant regulations.