Lions roar. Their roar can be heard eight kilometres away. As members of the genus Panthera, their epihyal bone in the voice box is replaced by a ligament, explains BBC Wildlife Magazine. "This can be stretched, creating a larger sound-producing passage and thus a wider range of pitch. The more the ligament extends, the lower the sound generated when air passes across the vocal cords. In addition, the cords are large, unbroken and fleshy, which produces deeper sounds."
However, unlike their roaring cousins, cheetahs have the ability to purr.
BBC explains that the bones of the cheetah’s voice box comprise a fixed structure, with divided vocal cords that vibrate with both inhaling and exhaling. "This structure is the same for all the ‘small’ cats. While this design enables these cats to purr continuously, it limits the range of other sounds and prevents them from being able to roar."