Specific sounds might be used to help encourage sleep regardless of environmental noises. (healthline.com)
In order to produce optimal magnetic detectors, the density of these defects should be increased without increasing environmental noise and damaging the diamond properties. (sciencedaily.com)
Keep environmental noise and light to a minimum; if you would be affected by the environment, chances are your toddler will be, too! (newkidscenter.com)