Sounds to cover noise

A steady, wide sound can make other sounds less noticeable, because it fills the gaps that voices, doors and traffic would otherwise stand out in. The key is that the sound covers the same range as the thing you want to blur. Low rumbles, like traffic or a thudding bass, are best covered by deep sounds such as brown noise. Speech and high clatter are covered well by broader, brighter sounds, such as white noise, fans, a waterfall or a steady rain. Eventful sounds do not cover well, since each change draws the ear. Set the volume just above the noise you want to blur, not far above it, and keep it comfortable.