The noise was limited to 1.0 to 1.5 pound-force per square foot (48 to 72 pascal) for the first twelve weeks, then increased to 1.5 to 2.0 psf (72 to 96 pascal) for the final fourteen weeks. This range was about equal to that expected from an SST. Though eight booms per day were harsh, the peak overpressures of 2.0 psf were supposedly an order of magnitude lower than that needed to shatter glass, and are considered marginally irritating according to published standards.