Sound insulation is the ability of a building or construction to reduce airborne noise between two rooms or between separate spaces without common openings. Examples of designs can be walls, doors, windows, glass sections, floor joists, valves dampers, screens and many more.
In most countries, including Sweden, there is a requirement for how much noise can be heard between different spaces, and these can be found in homes, schools, care centers, etc. Standards also provide opportunities to classify a building in different sound classes so that the market itself can control the construction of better soundproofing rooms for those who wish. Soundproofing can now be a competitive asset for real estate owners.
A construction, ex. wall or floor joints, sound insulation in a laboratory measurement is described with its weighted reduction rate Rw or weighted standardized noise level difference DnT, w. Additional measurements exist for specific elements. The higher the value of the reduction, the better the design reduces. The definition given at the beginning is given in decibels.
A laboratory measurement of the air sound insulation for a rail construction, eg. a wall is simplified so that you have two rooms with the wall between them. You place a speaker that sends out noise in one room. Then you measure the sound pressure level in both the room the source is in and in the second room without a sound source. This is done in some positions so that an average is available in each room. When simplified comparing these sound pressure levels with each other, one gets the difference, ie. sound insulation or reduction (Rw) value for the current wall structure.
The standards we use and are accredited for current laboratory measurements of air noise are SS-EN ISO 10140-1: 2016, SS-EN ISO 10140-2: 2010, SS-EN ISO 717-1 and related requirements for measurement procedures and requirements for measuring in SS-EN ISO 10140-4: 2010, SS-EN ISO 10140-5: 2010