If you normally sleep with a fan or sound machine at home... you can download an app on your smart phone and have your own portable sound machine on your phone. Use it while it's charging at night. My app has 2 'fan' sounds, a 'white noise' sound, a 'brown noise' sound, rainstorm sound, crashing waves, etc. It's really great for hotel rooms. My family used it on our family summer trip to Washington DC last summer. Works just great; it's small & portable!