Several years ago, in an office building near the 787 Dreamliner factory, a small group of Boeing engineers were quietly working on a lofty goal.

"We were trying to make the 787 airplane come out the quietest airplane of its size and capability," said noise engineer and Ballardite Mark Sandstrom.

Sandstrom and his colleagues set out to look for ways to make the jetliner quieter from tip to tail, participating in every facet of the Dreamliner's design.

The 787 features a new generation of engines with very high bypass-ratios; advanced acoustic linings; new engine inlets and nozzles; lightweight composite materials and a new, more aerodynamic wing.

The planes were recently tested for community noise levels in Glasgow, Montana, where flight test engineers embedded ultra-sensitive microphones along the runway of a secluded airfield. Boeing test pilots performed multiple takeoffs and approaches, testing each engine thrust setting to see how much noise the airplane generated.

Noise engineers found that for many of the test conditions, the 787 was so quiet as it approaches that you can hear birds chirping and cameras clicking until the airplane is right on top of the runway.

"We have to publish numbers to the one-tenth of a decibel, which is your human ear can't hear the difference," explained Sandstrom. "We have to define to that level of numerical precision."

Early data show the 787's noise footprint will be as much as 60% smaller than today's comparable airplanes, thanks to a host of design improvements.

Sandstrom said the 787's lightweight composite fuselage and more aerodynamic wing don't just help the airplane fly more efficiently, it also affects what people hear on the ground.

"If you climb higher on the same amount of energy and fuel, you've gotten further away from ears and microphones," says Sandstrom.

The results represent a big leap not only for Boeing but for the aviation industry.

"We have gone to great strides to try to reduce the noise signature of the airplanes to be better stewards of the environment, better stewards of the community," said Boeing test pilot Captain Craig Bomben.

"We can't expect to grow the number of airplanes higher and higher unless their environmental impact is minimized," added Sandstrom.

Watch the video, here.