Real world active noise cancellation using a multichannel DSP56001 system

Reports on the design and the real time performance of a portable active noise cancellation (ANC) system based around a PC hosted 20 MHz Motorola DSP56001 processor with a 4 channel analogue I/O board connected to the real world via standard consumer audio components. The system uses multi-channel filtered-X and filtered-U adaptive LMS algorithms, and includes facilities for on-line system identification. The linear response of this ANC system has been tested over the frequency range 65-500 Hz to easily produce cancellation of 20-40 dB for single tones and sums of a few tones. The authors present the performance of the ANC system when used to cancel a number of real world noises.<
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