EFFECTIVELY MASKS NOISE: Beloved by generations since 1962, Marpac is the trusted leader in white noise machines, and created the famous Marpac Sound – the soothing ambient sounds of rushing air. That sound that’s helped millions experience better sleep for generations is now available in this light and portable design. The Rohm effectively cancels out noises that may disturb or distract for improved sleep and concentration..This sound machine is intended for portable use and must be turned off and unplugged every 14 days