A filter which has a reduced output as the frequency is increased is called a rolloff filter. A tone control is a rolloff filter when turned down. Sometimes the attenuated portion of the frequency content of the signal itself is called rolloff. A circuit that attenuates a signal that is above (lowpass) or below (highpass) at specified frequencies. For example, microphones usually have a bass rolloff filter to remove wind noise and/or excessive breath pops.