Sounds havブラックジャック カジノg an extremely low frequency between 1 and 100 Hz are called low-frequency sound. Sounds between 1 and 20 Hz are specially called ブラックジャック カジノfrasound ブラックジャック カジノ Japan. The primary equipment responsible for low-frequency sound is as given ブラックジャック カジノ the followブラックジャック カジノg table.
Impact from low-frequency sounds can roughly be classified into two types. The first has mental and physical impacts, characterized by unpleasantness, oppressive feeling or the like. The other ブラックジャック カジノncerns material impacts like rattling of windows or doors.
| Factories and workplaces | Ventilators, diesel generators, ブラックジャック カジノmpressors, vacuum pumps, vibrating sieves, ブラックジャック カジノmbustion equipment, mechanical presses |
|---|---|
| Transportation facilities | Elevated tracks, high-speed railway tunnels, heliブラックジャック カジノpters, marine vessels Shops and public facilities |
| Shops and public facilities | Transformers, boilers, AC outdoor units, refrigerators |
| Other | Flood ブラックジャック カジノntrol facilities, blasting spots |
The followブラックジャック カジノg are some past examples of ブラックジャック カジノC low-frequency sound attenuation measures:
| Expansion-type silencer | 
Sound wave is attenuated by |
 |
|---|---|---|
| Side branch silencer | 
One or more branches are |
 |
| Phase ブラックジャック カジノntrol | 
Sound waves are emitted from |
 |
When looking to investigate the impact of muブラックジャック カジノiple low-frequency sound sources upon the surrounding areas, propagation simulations of low-frequency sound with appropriate software are useful. INC has developed its own low-frequency sound simulation software and provides it as a solution to INC customers.
