I read somewhere that if you talk to your cat - especially if you repeat the same words, in the same tone of voice, over and over - it will develop a larger "vocabulary" of feline vocalizations.
Well, I do talk to my cats in a somewhat ritualistic way, and I have noticed them making a surprising number of sounds. I may have mentioned them here before: the short "I'm here!" trill that broadcasts what they are doing to everyone in the apartment, similar but not identical to the "Uff da" chirp that they often make when they jump on or off a piece of furniture; the somewhat longer, giggy trill they make as they chase each other around the place; the unvoiced "Rowrrrr" that means "Just open this window and I'll show that rabbit/squirrel/bird/lizard a thing or two"; the low, ominous growl that I first heard when, as a very small kitten, Tyrone first saw his reflection in the bathroom mirror; the various inflections of "Meow" that can mean anything from a pathetic, simpering request to an imperious demand; the "You're stepping on my tail" shriek; the "Back off, you tail-crushing klutz" hiss; and even the series of monosyllabic "words" with which Tyrone and Lionel used to address each other before getting into a boxing match. But Sinead has recently topped them all with a new vocalization that totally blows me away.
Over the past week, I have heard it several times: a fairly long, monosyllabic "Meow" that oscilates between two or three pitches. It is often the first thing she says to me when I open the bedroom door in the morning - for, lately, I have taken to keeping the cats out of my bedroom while I sleep, since Sinead has a nocturnal compulsion to incessantly poke me with her paws.
I have also heard this "Tarzan Yell" meow first thing upon coming home from work. It only comes out once per occasion; after that, Sinead subsides to more conventional feline whimpers of supplication and interrogation, meows that mean "So? Can we play? Is it treat time yet? Are you going to stick around for a while? Hey! Pay attention to me!"
This yodeling yell seems to express all the impatience of a cuddly, companionable cat who hasn't had anyone to pay attention to her all night or all day: sort of a feline way of saying, "Where the #@%% have you been? If I have to spend one more minute without getting scratched behind the ears, I could go crazy!"