White noise machines may also make an excellent ... Choose from the soothing sound options of white noise, brook, thunder, summer night, ocean and rain. You can plug the Sound Spa into a wall ...

The Homedics SoundSleep White Noise Sound Machine plays six sounds, including steady white noise, summer night, ocean, thunder, brook, or rain. Instead of using a dial, it has buttons for each ...

Used in Greek theater to announce the entrances and exits of the gods, the original thunder-making machine was invented by Heron of Alexandria in the first century CE. Pulling the lever opens a trap ...