Abstract: Method and apparatus for entrainment containment in digital filters using output phase modulation. Phase change is gradually introduced into the acoustic feedback canceller loop to avoid entrainment of the feedback canceller filter. Various embodiments employing different output phase modulation approaches are set forth and time and frequency domain examples are provided. Additional method and apparatus can be found in the specification and as provided by the attached claims and their equivalents.

Abstract: A system providing method and apparatus to detect occurrence of an entrainment artifact and address it. The system analyzing a feedback canceller filter for certain characteristics that are associated with an entrained filter. When an entrained filter is detected, the feedback canceller filter is reset to a good filter that ideally represents the current approximate external acoustic feedback path without the characteristics of the entraining signal.