Robust process for managing filter coefficients in adaptive noise canceling systems

摘要

A system for managing the changing state of an adaptive filter in an active noise control (ANC) system is described. An adaptive filter state storage stores copies of prior states of the adaptive filter. A disturbance detector can detect either normal ambient noise or abnormal ambient noise. An adaptive filter state manager signals that a copy of a current state of the adaptive filter is to be repeatedly written to the state storage, so long as normal ambient noise is being detected. But when abnormal noise is detected, the state manager signals that the adaptive filter be restored to one of its prior states, from the copies stored in the state storage. Other embodiments are also described and claimed.

主权项

1. A system for managing the changing state of an adaptive filter in an active noise control (ANC) system, comprising:
an adaptive filter state storage that is to store copies of prior states of the adaptive filter; a disturbance detector; an adaptive filter state manager that is to a) signal that a copy of a current state of the adaptive filter be repeatedly written to the state storage so long as the disturbance detector is detecting normal ambient noise, and b) signal that the adaptive filter be restored to one of its prior states, from the copies stored in the state storage, when the disturbance detector detects abnormal noise; and an adaptive filter controller that is to update the state of the adaptive filter responsive to the state manager, wherein the state manager freezes the adaptive filter controller so that the controller stops updating the state of the adaptive filter, in response to the disturbance detector detecting abnormal noise, and wherein while the adaptive filter controller remains frozen, the ANC system is to produce anti-noise sound using the adaptive filter as configured into said one of its prior states.