Q: Our sound machine died, and my husband is shopping for a new one. It made sounds like rain and surf, which helped both of us sleep. The ads for some of the new machines talk about different colors ...

Ask enough sleep nerds about the best sound machines and two very different front-runners will ultimately emerge: the Dohm and the LectroFan. The Dohm, sold by a company called Yogasleep, is a ...