This is so true that on the nights it isn't raining, I sleep to the sound of artificial rain. though it simply can not compare to the real thing. The best thing to fall asleep to is the sound of a raging thunderstorm.
Even though this is for summer, I would do this every time of the year. In autumn/winter wrapped up in a blanket with a hot drink and toasting marshmallows and in summer/spring sitting on the beach watching the night unfold.