How do cats purr and where does the noise actually come from?
Despite being a universally recognized phenomenon, the exact mechanism by which the cat purrs has been frustratingly elusive for scientists. This is partly because the cat has no obvious anatomical feature unique to it that would be responsible. One hypothesis, backed up by electromyographic studies, is that cats produce the purring noise by fast twitching of the muscles in their larynx, which rapidly dilate and constrict the glottis, causing air vibrations during inhalation and exhalation. Combined with the steady inhalation and exhalation of air as the cat breathes, a purring noise is produced with strong harmonics. It was once believed that only the cats of the Felis genus could purr; some older texts may still say this. In fact, all cats are able to purr, although the cats of the Panthera genus (Tiger, Lion, Jaguar and Leopard) are only able to purr when exhaling. Cats, (big and small) are the only animals who purr. Contrary to popular belief, purring isn’t speaking.
