Patent US 5,113,389

In a noise cancellation system an adaptive filter produces a noise cancellation signal. The cancellation signal is compensated in response to indications of timing variations. For a linear traversal filter compensating coefficients (25) are provided which combine with, or relace, their respective primary coefficients when a timing variation occurs. Higher order compensating coefficients may be provided for selected taps and a modular structure is adopted thus facilitating implementation in integtrated form.