Abstract: The disclosure relates to a radio receiver module for receiving a signal having a lower side band and an upper side band, the module comprising: a noise detector configured to identify a noise frequency associated with an unwanted noise signal within the lower or upper side band; a filter configured to attenuate the noise frequency and increase gain at a mirror frequency within the signal in order to provide a filtered signal, wherein the mirror frequency is within the sideband that is unaffected by the unwanted noise signal and the mirror frequency corresponds to the noise frequency.

Abstract: An audio comparison method and apparatus compares audio streams by measuring the times of volume peaks in the audio streams and identifying correlations between the peaks in the audio streams, subject to possible delay between the streams. The audio comparison allows the identification of audio streams including the same audio content even in the presence of delay and distortion and using low processing power. The audio comparison has particular application in car radios to allow automatic retuning.