Active and passive noise control in practice on the Saab 2000 high speed turboprop

Low interior noise is an important comfort feature in all aircraft. Damping of propeller-generated noise in turboprop airliners has always been a major concern of aircraft manufacturers. Over the years different methods have been tried with varying levels of success. Active Noise Control(ANC) gives designers a potentially powerful tool for achieveing dramatic noise reduction. ANC systems are operational on both the Saab 340 and the high-speed turboprop Saab 2000 since 1994. In addition noise control measures in the Saab 2000 incorporates also a number of passive treatments and measures implemented already during the design stage. The resulting interior noise level is 76 dBA, averaged over all seats, at high cruise speed of 350 KTAS. This kind of interior noise level is compatible with turbo-fan powered aircraft of the same size.