The Method for Sound Insulation Testing
The method for testing for airborne and impact sound insulation testing methods is clearly presented in BS EN ISO 140-parts 4 & 7: 1998. The sound insulation rating methods that follow are defined in:
DnTw
The single figure rating method that gives the airborne sound insulation performance between two adjacent rooms within a building as measured within site conditions. The result achieved is affected not only by the separating element also by the surrounding structure and junction details.
Rating Method – Ctr
The Ctr adaptation term is a correction that can be added to either the RW (laboratory) or DnTw (site) airborne rating. The Ctr term is used because it targets the low frequency performance of a building element and in particular the performance achieved in the 100 – 315 Hz frequency range. This term was originally developed to describe how a building element would perform if subject to excessive low frequency sound sources, such as traffic and railway noise. This rating is expressed as RW + Ctr and allows the acoustic designer to critically compare performances. The rating method has not been universally welcomed.
RW
This single figure rating method is the rating used for laboratory airborne sound insulation tests. The figure indicates the amount of sound energy being stopped by a separating building element when tested in isolation in the absence of any flanking paths.
Rating Method – Lnw
This single figure rating method is the rating used forclaboratory impact sound insulation tests on separating floors. The figure indicates the amount of sound energy being transmitted through the floor tested in isolation, in the absence of any flanking paths. With impact sound insulation, the lower the figure the better the performance.
Rating Method – LnTw
The single figure rating method that is used for impact sound insulation tests for floors. The figure indicates the sound insulation performance between two adjacent rooms within a building as measured on site. The result achieved is affected not only by the separating floor but also by the surrounding structure, e.g. flanking walls and associated junction details.
Rating Method – Dncw
The single figure laboratory rating method, which is used for evaluating the airborne sound insulation performance of suspended ceilings. Laboratory tests simulate the room-to-room performance of the suspended ceiling when a partition is built up to the underside of the ceiling with sound transmitted via the plenum.
APT Sound Testing is UKAS accredited to undertake both Sound Insulation Testing and is also accredited to ISO 17025:2005 ‘General requirements for the competence of testing and calibration laboratories’. If you would like more information in regards to sound insulation testing and/or acoustic design, please contact us now at: info@aptsoundtesting.co.uk or call us on 07775623464