How long do they play for?
The soundbox is triggered through buttons in the ears and you can select from two tracks (white noise or lullaby), two volumes and two length of play back (20 min or 40 min).
Unless your little one takes a long time to settle, we recommend the 20 minute setting on Lullaby to really start that positive sleep association.
Why do they not play all night? Here's a handy blog post about that question.