i can let out a sound similar to purring but i only can do it when i breathe out while cats can do it on breathing in too! how do they do it???
Hi! Good question! I suppose every cat owner has tried to purr at least once in his life. Emotion: big smile Anyways here's what I found:

It turns out that cats have special wiring! The wiring travels from the brain to the muscles in the voice box, and this wiring is able to vibrate the muscles so that they act as a valve for air flowing past the voice box. The muscles work both during inhalation and exhalation, which creates the impression that cats can purr continuously. The air passes through the valve, which opens and closes rapidly to create the purring sound.

Take from here