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The U.S. Environmental Protection Agency authored a pamphlet in 1978 that suggested a correlation between low-birthweight (using the World Health Organization definition of less than 2,500 grams (88 oz)) and high sound levels, and also high rates of birth defects in places where expectant mothers are exposed to elevated sound levels, such as ...
For instance, two recognized sources of high-pitched sounds might be electromagnetic fields common in modern wiring and various sound signal transmissions. A common and often misdiagnosed condition that mimics tinnitus is radio frequency (RF) hearing, in which subjects hear objectively audible high-pitched transmission frequencies that sound ...
In musical notation, the different vertical positions of notes indicate different pitches. Play top: Play bottom: Pitch is a perceptual property that allows sounds to be ordered on a frequency-related scale, [1] or more commonly, pitch is the quality that makes it possible to judge sounds as "higher" and "lower" in the sense associated with musical melodies. [2]
Ululation (/ ˌ j uː lj ʊ ˈ l eɪ ʃ ən, ˌ ʌ l-/ ⓘ, [1] [2] from Latin ululo), trilling or lele, is a long, wavering, high-pitched vocal sound resembling a howl with a trilling quality. It is produced by emitting a high pitched loud voice accompanied with a rapid back and forth movement of the tongue and the uvula. [3]
The ear's shape also allows the sound to be heard more accurately. Many breeds often have upright and curved ears, which direct and amplify sounds. As dogs hear higher frequency sounds than humans, they have a different acoustic perception of the world. [24] Sounds that seem loud to humans often emit high-frequency tones that can scare away dogs.
A 1973 report cites a university study of fifty cases of people complaining about a "low throbbing background noise" that others were unable to hear. The sound, always peaking between 30 and 40 Hz (hertz), was found to only be heard during cool weather with a light breeze, and often early in the morning. These noises were often confined to a 10 ...
The Mosquito or Mosquito alarm is a machine used to deter loitering by emitting sound at high frequency. In some versions, it is intentionally tuned to be heard primarily by younger people. Nicknamed "Mosquito" for the buzzing sound it plays, the device is marketed as a safety and security tool for preventing youths from congregating in ...
High-amplitude sound of a specific pattern at a frequency close to the sensitivity peak of human hearing (2–3 kHz) is used as a burglar deterrent. [ 6 ] Some police forces have used sound cannons against protesters, for example during the 2009 G20 Pittsburgh summit , [ 7 ] the 2014 Ferguson unrest , [ 8 ] and the 2016 Dakota Access Pipeline ...