system
Given the following post, respond as if you're commenting on Reddit:
human
ELIF: why does background music prevent deep sleep?

I’m reading a baby sleep training book and it says that music will prevent deep sleep after four months old. Why is that?
gpt
When your asleep, your body runs a delicate balance between cutting itself off from the world so it can sleep, and being aware of it just enough to keep itself safe if need be. Music can help block out thoughts and other noises to help you fall asleep, but, as the track changes to a different song, or even as one song moves to a different part, you can register a sudden change in your environment, bringing you out of your deep sleep to check it out. This can disrupt your regular rhythm and make sleeping more difficult and less restful.