An international team of scientists from Austria, Switzerland and the Czech Republic has discovered the secret of cats’ purring. They concluded that pets purr thanks to special connective tissue pads placed on their vocal cords. To work published In the scientific journal Current Biology.
Since low-frequency sounds are usually produced by larger animals with long vocal cords, experts for a long time could not understand how cats manage to produce their characteristic low purr.
A new discovery suggests that a cat’s purring may be a passive aerodynamic effect that continues automatically after the brain sends an initial signal. This means pets do not need to constantly tighten their ligaments to purr.
“These low-frequency vibrations in the vocal cords trigger a special voice mode with an unusually long off coefficient,” the researchers write in the paper.
Purr pads consist of collagen and elastin fibers. Experiments have shown that these small (up to 4 mm in diameter) formations can produce humming as a result of self-sustained vibrations of the vocal cords. To purr, a cat only needs to breathe.
“Although our data do not completely reject the hypothesis that active muscle contraction causes purring, they do show that the cat’s larynx can readily produce purr-mode sounds with fundamental frequencies of 25 to 30 Hz without neural input,” the researchers said.
The reason why cats purr remains a mystery. Some theories suggest that purring is a sign of contentment and encourages more interaction with people. Research also suggests that purring may be a healing mechanism.
The study could lead to a new understanding of the role of purring in the health and well-being of cats. This will help scientists develop new technologies, such as ones that mimic the sound of purring, calming devices for cats, and even new methods to relieve pain and anxiety.
Psychologists before refuted Some harmful myths about cats.