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Vibroacoustic disease is a medical condition manifested in those who have had long-term exposure (≥ 10 yr) to large pressure amplitude (≥ 90 dB SPL) and low frequency noise (≤ 500 Hz). [1] The disease is said to lead to heart arrhythmia or even death. [2] [3] [4] [5]
The Hum is a name often given to widespread reports of a persistent and invasive low-frequency humming, rumbling, or droning noise audible to many but not all people. Hums have been reported all over the world, including the United States, the United Kingdom, Australia and Canada.
Bloop is the name given to an ultra-low-frequency and extremely powerful underwater sound detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) in 1997. The sound is consistent with the noises generated by icequakes in large icebergs, or large icebergs scraping the ocean floor. [3]
Annoyance effects of noise are minimally affected by demographics, but fear of the noise source and sensitivity to noise both strongly affect the 'annoyance' of a noise. [42] Sound levels as low as 40 dB(A) can generate noise complaints [43] and the lower threshold for noise producing sleep disturbance is 45 dB(A) or lower. [44]
[79] [80] This noise pollution significantly raises the low-frequency ambient noise levels above those caused by wind. [81] Animals such as whales that depend on sound for communication can be affected by this noise in various ways. Higher ambient noise levels also cause animals to vocalize more loudly, which is called the Lombard effect ...
The report "A Review of Published Research on Low Frequency Noise and its Effects" [54] contains a long list of research about exposure to high-level infrasound among humans and animals. For instance, in 1972, Borredon exposed 42 young men to tones at 7.5 Hz at 130 dB for 50 minutes.
The sound created by wind turbines is caused by the blade rotation similar to aircraft propellers. Because the rotation rate is low, the frequency is also low, but the large size of many can result in disturbing sound levels, particularly in high wind areas. [34] Most local control is done by advantageous site planning.
Low frequency noise is attenuated worse than mid- and high-frequency noise. Most employers did not have the means to measure the noise spectrum. It was assumed that the average noise attenuation in workplaces is about the same as in laboratory conditions. It was believed that the differences in noise attenuation among different workers are small.