Pub. L. 115-254, div. B, tit. I, subtit. D, sec. 188
STUDY REGARDING DAY-NIGHT AVERAGE SOUND LEVELS.
SEC. 188. STUDY REGARDING DAY-NIGHT AVERAGE SOUND LEVELS.(a) Study.—The Administrator of the Federal Aviation Administration shall evaluate alternative metrics to the current average day-night level standard, such as the use of actual noise sampling and other methods, to address community airplane noise concerns.(b) Report.—Not later than 1 year after the date of enactment of this Act, the Administrator shall submit to the appropriate committees of Congress a report on the results of the study under subsection (a).