There are two things I hate about traveling. Packing and sleeping in a foreign place. I can't avoid packing, but I've figured out a way to sleep comfortably anywhere I go with this soothing tranquility app called RAIN RAIN.
You can also set a timer. The sounds can be set to gently fade out after certain intervals when you sleep so that you battery won't go to waste. I usually set mine to 1 hour. The rain mix I've set up for myself knocks me out every time no matter where I lay my head!
Try it out!