A noise-cancellation method, comprising the steps of: receiving a value from a noise sensor at a time step; storing the received value in a buffer, the buffer having a length, the buffer further storing a number of additional values, wherein an end value is removed from the buffer to accommodate the received value; providing a previously-computed result, wherein the previously-computed result represents the sum of the square of the values stored in the buffer at a previous time step; adding a square of the received value to the previously-computed result and subtracting a square of the end value from the sum of the received value and the previously computed value in order to yield a newly-computed result and updating a plurality of coefficients of an adaptive filter according to, in part, the value of the newly-computed result.