A method for operating a signal filter device for performing an acoustic echo cancellation on an input signal with respect to a reference signal, the signal filter device including, M adaptive filters, M first analysis filters, M second analysis filters, and a controller, M being an integer above two, the method comprising: processing, by the M first analysis filters, the input signal to generate M first sub-band signals, the input signal including a near-end signal, each first sub-band signal being output by one of the M first analysis filters; processing, by the M second analysis filters, the reference signal to generate M second sub-band signals, the reference signal including a far-end signal, each second sub-band signal being output by one of the M second analysis filters and corresponding to one of the M first sub-band signals; obtaining, by the controller, for each of the M first sub-band signals, a correlation parameter indicating a correlation between the first sub-band signal and the corresponding second sub-band signal; and adjusting, by the controller, the working states of the M adaptive filters based on the correlation parameters for the M first sub-band signals, wherein the working states of the M adaptive filters indicate whether the M adaptive filters work or not; wherein the adjusting the working states of the M adaptive filters comprising: detecting, by the controller, whether a first condition is satisfied based on the obtained correlation parameters; and in response to a detection that the first condition is satisfied, causing, by the controller, at least one target adaptive filter of the M adaptive filters to stop working; wherein: the M first sub-band signals corresponds to M sub-band indexes ranging between 0 and M-1; and the detecting whether a first condition is satisfied based on the obtained correlation parameters comprises: identifying, by the controller, in each period of N consecutive periods, a first index of the M sub-band indexes corresponding to the maximum correlation parameter of the period, wherein N is an integer above 1; and detecting, by the controller, that a second condition is satisfied based on the first indexes of the N consecutive periods. processing, by the M first analysis filters, the input signal to generate M first sub-band signals, the input signal including a near-end signal, each first sub-band signal being output by one of the M first analysis filters; processing, by the M second analysis filters, the reference signal to generate M second sub-band signals, the reference signal including a far-end signal, each second sub-band signal being output by one of the M second analysis filters and corresponding to one of the M first sub-band signals; obtaining, by the controller, for each of the M first sub-band signals, a correlation parameter indicating a correlation between the first sub-band signal and the corresponding second sub-band signal; and adjusting, by the controller, the working states of the M adaptive filters based on the correlation parameters for the M first sub-band signals, wherein the working states of the M adaptive filters indicate whether the M adaptive filters work or not; wherein the adjusting the working states of the M adaptive filters comprising: detecting, by the controller, whether a first condition is satisfied based on the obtained correlation parameters; and in response to a detection that the first condition is satisfied, causing, by the controller, at least one target adaptive filter of the M adaptive filters to stop working; detecting, by the controller, whether a first condition is satisfied based on the obtained correlation parameters; and in response to a detection that the first condition is satisfied, causing, by the controller, at least one target adaptive filter of the M adaptive filters to stop working; wherein: the M first sub-band signals corresponds to M sub-band indexes ranging between 0 and M-1; and the detecting whether a first condition is satisfied based on the obtained correlation parameters comprises: identifying, by the controller, in each period of N consecutive periods, a first index of the M sub-band indexes corresponding to the maximum correlation parameter of the period, wherein N is an integer above 1; and detecting, by the controller, that a second condition is satisfied based on the first indexes of the N consecutive periods. identifying, by the controller, in each period of N consecutive periods, a first index of the M sub-band indexes corresponding to the maximum correlation parameter of the period, wherein N is an integer above 1; and detecting, by the controller, that a second condition is satisfied based on the first indexes of the N consecutive periods.