Ernie identifies noises.
Is it possible to be too considerate? So many Bert & Ernie sketches could be resolved by Ernie thinking about Bert's feelings. In this instance, if he were less concerned about Bert's feelings and possible reactions, they could probably both get a lot more sleep.
At the top of this sketch when Ernie says, "Bert, I can't sleep," my reaction is to say, "How do you know? You didn't even try!"