Like compressors and limiters, expanders and gates effect the dynamic range, but expanders and gates produce the opposite effect compared to compressors and limiters. Instead of decreasing the dynamic range, the difference between the loudest and quietest sounds, they increase an expander or gate when the volume drops below a threshold level, these devices automatically attenuate, or turn down the volume. An expander will have a higher threshold and gentler attenuation when audio levels drop below this point. A gate will have a lower threshold and a more sever attenuation that usually produces a hard mute, when the audio level drops below the and gates are most often used to minimize noise, bleed, and increase presence by turning down or turning off tracks that are not picking up direct sound from the mic.