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They are emitted by animals such as bats and rodents, and have been extensively studied in rats and mice. As opposed to sonic vocalizations, ultrasonic vocalizations cannot be detected by the human ear. USVs serve as social signals, [2] and are categorized according to their frequency.
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. Researchers have found that humpback whales' song lengths were longer when low-frequency sonar was active nearby. [82]
Ultrasound is used to evaluate fat thickness, rib eye area, and intramuscular fat in living animals. [48] It is also used to evaluate the health and characteristics of unborn calves. Ultrasound technology provides a means for cattle producers to obtain information that can be used to improve the breeding and husbandry of cattle.
Ultrasound is sound waves with frequencies higher than 20,000 Hz. Ultrasound is not different from audible sound in its physical properties, but cannot be heard by humans. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz. Medical ultrasound is commonly used for diagnostics and treatment.
Sound from ultrasound is the name given here to the generation of audible sound from modulated ultrasound without using an active receiver. This happens when the modulated ultrasound passes through a nonlinear medium which acts, intentionally or unintentionally, as a demodulator .
Hearing range describes the frequency range that can be heard by humans or other animals, though it can also refer to the range of levels. The human range is commonly given as 20 to 20,000 Hz, although there is considerable variation between individuals, especially at high frequencies, and a gradual loss of sensitivity to higher frequencies ...
Traffic noise has several negative effects, including increased risk for coronary artery disease, with night-time exposure to noise possibly more harmful than day-time exposure. [2] It has also been shown to increase blood pressure in individuals within the surrounding residential areas, with railways causing the greatest cardiovascular effects.
Electronic pest control is the name given to any of several types of electrically powered devices designed to repel or eliminate pests, usually rodents or insects. Since these devices are not regulated under the Federal Insecticide, Fungicide, and Rodenticide Act in the United States, the EPA does not require the same kind of efficacy testing that it does for chemical pesticides.