In our store experience, the most popular and effective sound machines are made by the Marpac Corporation right here in the USA. The sound machines by Marpac include the most popular and highly rated Dohm DS and its counterpart, the Dohm SS. The DS and SS designations are simply meant to stand for Double Speed and Single Speed respectively. I have talked to many people over the years that who have been helped by using the SleepMate lineup of sound machines as an aid in sleep.
The Dohm DS sound machine by Marpac produces a clean, pleasant fan-like sound of rushing air by using an actual electric motor to spin a fan wheel inside the case. The most notable difference between Marpac mechanical sound machines and others is that they don’t loop. Looping refers to playing a short recorded segment of sound over and over in a constant loop. the Dohm sound machines don’t loop and this is important since if you can detect looping in white noise machine, it can prove to be a real distraction. The Marpac Dohm sound machines are all quality made in the USA and the superior quality is apparent when compared to cheaper models made in China. The Dohm produces its fan-like sound with a small motor. This rushing air sound has proven to be pleasing to most people who try it.