A dog whistle (also known as silent whistle or Galton's whistle) is a type of

whistle A whistle is an instrument which produces sound from a stream of gas, most commonly air. It may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a lar ...

that emits sound in the

ultrasonic Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies fr ...

range, which humans cannot hear but some other animals can, including

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

s and domestic

cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

s, and is used in their

training Training is teaching, or developing in oneself or others, any skills and knowledge or fitness that relate to specific useful competencies. Training has specific goals of improving one's capability, capacity, productivity and performance. I ...

. It was invented in 1876 by Francis Galton and is mentioned in his book ''Inquiries into Human Faculty and Its Development'',Galton, Francis (1883)
''Inquiries into Human Faculty and Its Development''
pp. 26-27. in which he describes experiments to test the range of frequencies that could be heard by various animals, such as a house cat. The upper limit of the human hearing range is about 20 kilohertz (kHz) for children, declining to 15–17 kHz for middle-age adults. The top end of a dog's hearing range is about 45 kHz, while a cat's is 64 kHz. It is thought that the wild ancestors of cats and dogs evolved this higher hearing range in order to hear high-frequency sounds made by their preferred prey, small rodents. The frequency of most dog whistles is within the range of 23 to 54 kHz, so they are above the range of human hearing, although some are adjustable down into the audible range. To human ears, a dog whistle makes only a quiet hissing sound. The advantage of the dog whistle is that it doesn't produce a loud irritating noise for humans that a normal whistle would produce, so it can be used to train or command animals without disturbing nearby people. Some dog whistles have adjustable sliders for active control of the frequency produced. Trainers may use the whistle simply to gather a dog's attention, or to inflict pain for the purpose of

behaviour modification Behavior modification is an early approach that used respondent and operant conditioning to change behavior. Based on methodological behaviorism, overt behavior was modified with consequences, including positive and negative reinforcement continge ...

. In addition to lung-powered whistles, there are also electronic dog whistle devices that emit ultrasonic sound via

piezoelectric Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied mechanical stress. The word '' ...

emitters. The electronic variety are sometimes coupled with bark-detection circuits in an effort to curb barking behaviour. This kind of whistle can also be used to determine the

hearing range Hearing range describes the range of frequencies 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 variati ...

for people and for physics demonstrations requiring ultrasonic sounds.

References

{{Whistles

Whistle A whistle is an instrument which produces sound from a stream of gas, most commonly air. It may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a lar ...

Whistles

cs:Galtonova píšťala

See also

References