Electro-Harmonix Silencer Noise Gate and Effects Loop PedalThe Electro Harmonix Silencer Noise gate and Effects Loop pedal is a sophisticated noise gate that can tame a single pedal or an entire effects loop. The Silencers three control layout provides precise fine tuning to fit your system, axe and playing style. Threshold adjusts how much level is required to open the noise gate and allow a signal to pass thru. Reduction regulated the degree to which the gated signal is reduced and is variable between 70dB