US airport significant noise exposure fell from seven million to five hundred thousand

Evidence

That number has fallen—2005 is the last year on this chart—to around five hundred thousand, — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 1523

Categorization

• corroborated: 2 independent passages support this claim — Gordon Hempton, John Grossmann, One Square Inch of Silence- One Man’s…, 1523