Low-frequency noise around 100 Hz is considered relatively common, mainly due to several reasons:
1.Mechanical vibration: Many mechanical devices, such as generators, fans, air conditioning compressors, etc., often operate at frequencies between tens of hertz and hundreds of hertz. When these machines are in operation, their vibrational frequencies may produce low-frequency noise related to their rotational speed or operating mechanism, with frequencies around 100 hertz being common.
2.Grid frequency: In many regions, the standard frequency of AC grids is usually 50 Hz or 60 Hz. Electrical equipment and systems in the power grid can introduce associated noise, including low-frequency noise components with frequencies around 100 Hz. In addition, grid equipment such as power transformers and transmission lines can also generate low-frequency vibrations and noise.
3.Environmental factors: Some environmental factors can also contribute to low-frequency noise, such as the sound of wind, water flowing, etc. The noise produced by these natural phenomena tends to have a low-frequency component and may have a large energy in the frequency range of around 100 Hz.
4.Acoustic properties: Low-frequency sounds have better penetration and propagation than high-frequency sounds as they travel through the air, so even low-frequency vibrations generated at a distance may be heard at greater distances. This makes low-frequency noise of around 100 Hz even more pronounced in indoor and urban environments.
In summary, low-frequency noise around 100 Hz is relatively common, mainly due to a combination of factors such as mechanical vibration, grid frequency, environmental factors, and acoustic characteristics.