Animal communication is a fascinating topic, and one which is particularly interesting because us humans do it in such a complex way! Humans are the only animals to have evolved language – and we can express this language in written, spoken and sign form.
In terms of sound expression of communication, we have evolved a particularly complex ‘sound system’ which allows precise control of what comes out of our mouths. It is likely that the evolution of this precise system came alongside the development our of temporal lobes – which regulate speech (amongst other things). Cats have not evolved any capability for language, and so do not have a temporal lobe, and so do not have a particularly complex system of speech!