You are required to undertake two types of sound testing to comply with Building Regulations Part E, they are Airborne and Impact sound tests. Airborne sound tests are undertake on wall and floors and impact tests are undertaken on floor only.
To test the sound insulation properties of a floor or wall via airborne sound testing, you need to provide a sound source which consists of an amplifier and loud speaker is set up on one side of the wall or floor partition that is to be tested. We then turn the setting to turn on Pink noise. Pink noise sounds like the static that can be heard on a radio that is off station. Pink noise is used because it is made up of a wall of sound that has a wide spectrum of frequencies. This provides an indication of sound insulation performance for a wide range of sounds that may be experienced within a dwelling from musical instruments to loud TV noise sources.
The pink noise is measured in the room which contains the speaker or sound source using a Class 1 Norsonic sound level meter; thereafter the noise is measured on the other side of the wall or floor partition that is being tested. In layman’s terms the difference between these two levels is the amount of sound that is stopped by the sound insulating qualities if the wall or floor partition/s. The result is then corrected and adjusted depending on the echo or reverberation time within the receiving room, and any background noise such as builders work noise etc.
To test the impact sound insulation performance of a floor, a Norsonic tapping machine which consists of five small hammers that are dropped onto the floor to simulate foot fall, is placed on the floor. The resultant noise in the room below is measured with a Norsonic Class 1 sound level meter and the amount of noise that passes through the floor is the impact sound transmission level and is expressed as a single number. This result is then corrected and adjusted depending on the reverberation time of the rooms as well as any background noise to give the impact sound transmission result (LnT,w).
Both types of sound tests results are then compared to the performance criteria of Approved Document E, which stipulates that airborne sound needs to achieve 45dB for new build & 43dB for conversion projects. To achieve a pass for impact sound testing you need to achieve 62dB for new build & 64dB conversions.