The cheetah has a completely ossified hyoid apparatus and is traditionally classified among cats that can purr but cannot roar.
The hyoid apparatus is a group of small bones and supporting structures associated with the tongue, throat, and larynx. In the traditional explanation of cat vocalizations, cheetahs and other “purring cats” have a more fully ossified hyoid, keeping the larynx relatively close to the skull. Lions, tigers, jaguars, and leopards have a less completely ossified hyoid and specialized larynges that permit roaring.
This is one reason cheetahs sound unlike lions or tigers. They can purr, chirp, hiss, growl, and make birdlike calls, but they do not produce the deep, resonant roar associated with Panthera cats. Their vocal anatomy reflects their evolutionary placement outside the genus Panthera.
The simple hyoid rule is useful but not absolute: modern anatomical research has questioned whether hyoid ossification alone determines purring. The cheetah answer nevertheless remains the canonical one for this standard zoology question.