The Original Sound Conditioner first introduced in 1962; now in its 4th generation design. Instead of a digital (electronic) recording, it has a built-in fan that creates the sound of rushing air. The Dohm-DS consists of a compact adjustable acoustic housing surrounding a two-speed electric motor with a unique asymmetrical fan. This design allows it to create the soothing sound of rushing air, the Marpac Signature Sound, without the disturbance of actual moving air. This all-natural "white noise" sound has been proven to effectively block noises at a broad range of frequencies, so you can get deep, undisturbed sleep all night long. The Dohm’s two speeds and adjustable tone and volume allow you to control your personal sound environment with the simple twist of a wrist. Choose high or low speed, then twist the cap to increase or decrease the size of the sound hole openings. By adjusting the speed and sound openings, you will customize the volume and tone to find a soothing white noise that's ideal for you. Features an 8' cord, and comes in three color options: white, black and tan.