We've used our old Dohm Noise Machine every night for many years, and it's never failed us. It's heavy because it is so robustly made, and I'm sure that this is a big part of why it works so well, for so long. The sound is produced by a fan moving air through baffles, so the sound is very consistent, compared to digital noisemakers. We purchased a second Dohm machine when our grandson started staying overnight with us, and it is identical in design and materials to our first, and works just as wSee full review