Purring
Purring is a noise that a domestic cat or possibly other creatures apparently make to indicate well-being. A cat will also sometimes purr when it is uneasy or nervous, to seek reassurance. Female cats are also known to purr while giving birth.Science still does not know how cats purr, but one theory holds it involves cats' false vocal cords, the other involving blood hitting the aorta. Some cats seem to be able to meow without interrupting the purring noise.
The feline purring noise is proven to have positive effects on cell regeneration. Its frequency is assumed to reduce the sensation of pain as well.
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