It is high-pitched, loud, and nonstop at times. When he receives a lot of attention, the high-pitch really kicks in, like a meow. What I discovered, though, was that no one really knows how or why cats purr. The standard explanation is that this contented-sounding murmur is the result of a vibration of the false vocal cords, two folds of membrane behind the true vocal cords in the larynx. But not everyone accepts this theory.
Some cats never seem to purr, while others seemingly never stop.
It's all very individual. One thing that appears certain is that cats don't purr when they feel threatened or are angry, although they may purr when they are sick or dying. Ask your veterinarian to check your kitten's throat and listen to his lungs during his next checkup. If he doesn't stop purring while your vet is trying to listen to his lungs, the doctor might want to try again after inserting a rectal thermometer or running water in the sink. Enjoy your new kitten.