Abstract
These days, the subject of noise and low-frequency sound, such as a wind-power-generation and a residential heat pump water heater (Eco Cute), is taken up in mass media etc.
In the 2010 fiscal year, the noise complaints that were brought to local governments in japan were more than 15,000 affairs, and the low-frequency sound complaints were only 250 affairs.
Although there are not many numbers of low-frequency sound complaints, the upward tendency is shown every year. In addition to those numbers, many unreported complaints may exist.
How to advance in an anti-noise measure has been changing from the conventional measure against symptomatic therapy to the measure against prevention recently, and the noise of a machine, a factory, etc. must be considered increasingly in a planning or a design phase.
Here, the foundation of noise and low-frequency sound, the target, standard and index of a measure, and investigation and measure, prevention technology, etc. are explained.
And, the practical use situation to the design example of a large-scale sound barrier, comparatively new active-noise-control technology for three-dimensional space noise, such as construction task noise, etc. are explained.
