The first time your baby hears his or her own voice played back is a moment to remember. Your baby may not even realize who it is for a while, and watching him or her figure it out is a lot of fun. This activity is a winner anytime, but it's easiest in the quiet hour before bed.

Appropriate for: 5 months to 3 years
Skills developed: Auditory, verbal
What you'll need: A recording device

An old-fashioned tape recorder will work for this activity, as will a digital audio recorder. Set up the recording device near your baby and then encourage your baby to start babbling: Open a picture book, tickle his or her feet, or wave a toy (you'll want to choose something that allows you to be quiet, because it's most fun if the recording doesn't have a lot of sound other than your baby's voice).

Once you have a good sample of your baby's vocal range (this may take more than one sitting), play it back. When you get a quizzical expression, reply, "Yes, that's you!" and play the key moments over the next few months until the revelation hits. Save the tape or audio file, as it will be a great memento to add to your photos and videos.