Processing a signal comprising signal distortions with filters. The filters comprise a first filter configured to a first time scale to compensate for signal distortions within respective symbols of the signal and a second filter configured to a second time scale to compensate for signal distortions among symbols of the signal. A probability estimate is produced based on an output of at least one of the first and second filters. At least one of the first and second time scales is adjusted according to the probability estimate.