Agricultural machines generate a complex noise field with significant low-frequency components. The demands for good sound comfort of the driver inside cabins of these machines are continuously growing. Since passive control techniques are not able to efficiently reduce the low-frequency noise in the cabin, active noise control techniques are being explored. A zone of quiet around the ears of t...

A noisy environment dominated by low frequency noise can often be improved through the use of active noise control. This situation arises naturally in propeller aircraft where the propellers induce periodic low frequency noise inside the cabin. The cabin noise is typically rather high, and the passenger flight comfort could be improved considerably if this level were significantly reduced. This...

In this paper, we present the development and evaluation of an integrated active noise control (ANC) communication headsets. This integrated system provides cancellation of noise that corrupted both the transmitted near-end speech and the received far-end speech. It utilizes an adaptive feedback ANC filter to reduce acoustic noise that corrupts the far-end signal inside the ear cups of headsets...

The noise levels in the passenger cabin of turbopropeller-driven aircraft are typically higher than the noise levels in comparable turbofan-powered aircraft. The sources of noise in a turboprop aircraft include boundary layer flow noise, structure-borne noise due to engine vibration, and acoustic excitation of the fuselage due to the propeller, with the latter being dominant for most turboprop ...

We present a mathematical framework for the active control of time-harmonic acoustic disturbances. Unlike many existing methodologies, our approach provides for the exact volumetric cancellation of unwanted noise in a given predetermined region of space while leaving unaltered those components of the total acoustic field that are deemed friendly. Our key finding is that for eliminating the unwa...