A cat purring is a distinct vibrating sound of varying duration, often in a low pitch, that is generated by vibrations in the range of 20 to 50 hertz (according to Elisabeth von Muggenthaler, a bioacoustic specialist at the Fauna Communication Institute in North Carolina). This mode is pleasant to the human ear, it does not cause anxiety and irritation. This article will help answer two main questions. “Why do cats purr?” and “How do cats purr?”