As described in the book, you can use the crying baby clip to:

Desensitize your pet – Before the baby arrives, play the clip to get the pet used to the loud, high-pitched screams. Dogs, in particular, have a keen sense of hearing, and may panic upon first listen, but eventually they adjust. It can help to desensitize you as well.

Take a sick day – Now that you have a baby, you have so many more excuses to play hooky from work. You’re sick, the baby’s sick, the sitter’s a no-show, and so on. When calling your boss, play the clip in the background during the conversation. With it, no one will have the nerve to question you.

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