Active noise cancellation using frequency response control

摘要

An active noise cancellation system (20) includes using a frequency domain response of a secondary path (44) of the system. The frequency domain response information provides an indication of a desired magnitude and phase of a reference signal that is used for generating a cancellation signal that drives a speaker (28) to achieve the desired amount of noise cancellation. Using a frequency domain response greatly reduces the number of computations required and the amount of memory used within the system controller. In one example, a reference signal adjustment module (40) applies the desired magnitude and phase adjustments to a reference signal having a known frequency. In another example, the referenced signal tone generator (22, 40) incorporates the desired amplitude and phase in the reference signal.