In the wild, cats tend to become less vocal as they mature. Even vocal kittens grow into relatively quiet adult cats. The classic chirrup sound is one of the most common vocalisations. However, domesticity and close proximity with noisy humans has resulted in most cats continuing to be vocal (or even becoming chattier) as they grow older. Adult cats living with humans tend to have a much wider repertoire of sounds than cats living in the wild, which they make by changing the positioning of their mouths.
Hissing or growling is a common method of communicating aggressive or defensive feelings, and its meaning is generally very clear. If this warning is not heeded, the cat may well deliver a nip or a swipe of the paw. Grumbling is also very common, but this can be either aggressive or benign sometimes being used simply to get the attention of a human companion.
The all-purpose meow can be adapted to fit almost any situation and its meaning is more easily read by considering the body language of the cat. Shorter versions of this are “mwp” and “brrp” which generally seems to mean “look at me!” or “do something”. If this attention is required urgently, or the cat is feeling somewhat despondent, a cat may yowl in quite a mournful way.
Higher pitched noises tend to be friendly or demanding of attention, while lower pitched noises have a more negative aspect and can indicate displeasure or aggression.
Some cats make a strange chattering noise when observing potential prey. This sound may be intended to display their excitement (or frustration if they cannot get to the prey), or it may be an attempt to replicate the sound of the prey animal.
It is also possible that this noise represents “rehearsal behaviour” because it is thought that it may be a practice run for the biting movement with which they plan on despatching their prey. Occasionally, a cat will snort if their attempt to catch something has ended in failure.