Although cats regularly communicate with one another and their human companions through body language, they also use vocal sounds to communicate. From hissing to purring, cat vocalization can be subtle or demanding. Orientals, Siamese in particular, usually have loud, raucous voices, while other cats (typically longhairs) can have soft ones that are almost inaudible to humans.

A cat's meow to her owner may mean "It's time to eat," "I need to go out" (or "My litter tray needs changing"), "Come here and look" or a number of different things. Her purr usually means contentment or pleasure, while a hiss can be a warning to "Stop it!" or "Go away and leave me alone."

Among cats, vocalization is often more strident, taking on a threatening quality, especially if they are strangers or an unknown cat wanders into another's territory.

An attentive owner will usually be able to discern the different sounds and qualities of his cat's vocalizations. When he does, he will have gained one more step in learning Cat Speak.