; (B) the threshold of aircraft noise at which health impacts are felt; and (C) the effectiveness of aircraft noise abatement programs at airports around the United States. (4) Report (A) In general Not later than 2 years after the date of enactment of this Act, the Administrator shall submit to Congress a report on the results of the study conducted under paragraph (1). (B) Requirements The report submitted under subparagraph (A) shall include specific recommendations on new measures that can be implemented to mitigate the impact of aircraft noise on surrounding communities. (e) Conforming amendment The Noise Pollution and Abatement Act of 1970 ( Public Law 91–604 ; 84 Stat. 1709) is repealed. 4. Grants under Quiet Communities Program Section 14 of the Noise Control Act of 1972 ( 42 U.S.C. 4913 ) is amended— (1) in subsection (b)— (A) in the matter preceding paragraph (1) by striking but not limited to ; (B) in paragraph (2) by striking sections 6, 7, and 8 of this Act and inserting section 6 or 8 of this Act, or section 44715 of title 49, United States Code ; and (C) by redesignating paragraphs (1) through (5) as subparagraphs (A) through (E), respectively, and indenting appropriately; (2) in subsection (c)— (A) in the matter preceding paragraph (1) by striking but not be limited to and inserting in accordance with the Federal authority pursuant to this Act to regulate sources of noise in interstate commerce ; (B) in paragraph (1)— (i) in subparagraph (C) by striking and, at the end; (ii) by redesignating subparagraphs (A) through (D) as clauses (i) through (iv), respectively, and indenting appropriately; and (iii) by adding at the end the following: (v) establishing and implementing training programs on use of noise abatement equipment; and (vi) implementing noise abatement plans; ; (C) by striking the undesignated matter following paragraph (5); and (D) by redesignating paragraphs (1) through (5) as subparagraphs (A) through (E), respectively, and indenting appropriately