A nighttime noise complaint was issued from the residential area near one of Wärtsiläs main large 4-stroke medium speed engine factories located in downtown Vaasa. The facility produces about 500 engines per year and every engine is subjected to a test run. An investigation found that the likely source of the intolerable noise was from the exhaust from an engine 1000 hour endurance test. Although they discovered the source of the noise, they were unable to solve the noise problem completely.
Architects and acoustic consultants struggle to accurately estimate the vibration reduction index for their building designs. ISO 10848 defines a method for measuring this, but it is a long, tedious and expensive process which is implemented by building two rooms and their junctions one by one, exciting the wall and measuring the flanking and direct noise. This process must be done for each building design. When the design changes or the desired results are not achieved, the structure must be demolished and built again from the beginning.