Patent ID: 7656933

Claim:
A method for suppressing periodic interference signals in an input audio signal which has been subjected to interference, the method comprising: determining a period length for a substantially periodic interference signal in the input audio signal; using the determined interference period length to generate a multiple-superposition signal by: identifying a particular time period of the input audio signal having a duration equal to the determined interference period length; superimposing the particular time period onto multiple previous time periods of the input signal, each having a duration equal to the determined interference period length, wherein the multiple superpositioning processes results in an increased amplification of interference signals located at the same place, and further results in an increased removal of useful signals from the input audio signal; obtaining a further signal by scaling the generated multiple-superposition signal, wherein the further signal corresponds to the substantially periodic interference signal; and subtracting the further signal from the input audio signal which has been subjected to interference in order to generate a further input audio signal on which interference suppression has been performed.