How do cats purr? New finding challenges long-held assumptions

One of the most delightful sounds to a cat lover is their feline friend’s rumbling noise when they get a little scritch behind the ears. Yet how cats produce their contented purrs has long been a mystery. A new study may finally have the answer. Domestic cats possess “pads” embedded within their vocal cords, which add an extra layer of fatty tissue that allows them to vibrate at low frequencies, scientists report today in Current Biology . What’s more, the larynx of these animals doesn’t appear to need any input from the brain to produce such purring . “Purring has historically had a complex, nonscientific explanation,” says Bonnie Beaver, a veterinary scientist at Texas A&M University who wasn’t involved in the study. Nonscientific, she says, because although scientists had devised various theories to resolve the mystery, few were ever tested. The new study, Beaver says, is a good step forward. Domestic cats are small, with most weighing about 4.5 kilograms, and researchers had puzzled over how these animals manage to generate the low-frequency vocalizations—typically between 20 and 30 hertz (Hz)—involved in purring. Such frequencies are usually only observed in much larger animals, such as elephants , which have far longer vocal cords. And whereas big cats such as lions and tigers are capable of loud roars, domestic cats are only able to produce low-frequency purring. Most mammal vocalizations, in...
Source: ScienceNOW - Category: Science Source Type: news