cat's meow

What is the meaning of a cat’s meow that grows louder and louder?

I explored this question in my book "The Cat's Meow: How Cats Evolved from the Savanna to Your Sofa."

One type is onomatopoeia; for example, words that describe a cat’s meow or a rooster’s crow are similar across many languages.

“The Cat’s Meow,” a comparable painting from the same year, is in the collection of Jasper Johns.

“You are simply the cat’s meow.”