How do you meditate with a cat purring in your ear?

You meditate with a cat purring in your ear in the same way you meditate with bright, flashing, neon lights in your eyes. You simply watch. You watch your thoughts, feelings, and sensations. You notice the sound of purr, or the flash of light. You notice your reactions to these things. You notice your judgments: "this cat is so cute," or "this light is so annoying!"

You simply notice whatsoever is happening, being neither for nor against it. You are a simple, neutral observer. You don't try to change or fix anything. You just take note of what is happening.