Ducker

Ducker blocks are used to duck (attenuate) one signal when the level of another signal exceeds a specified threshold.  The unlabeled input on the upper left side of the Ducker block is for the input signal (i.e., the signal to be ducked).  The input labeled with an S is the sense signal, which is the signal that will trigger ducking to occur when it exceeds the threshold.

DSP Block Representation

More information on logic is located here: Ducker

Control Dialog

Ducking can also be triggered via a logic signal instead of an audio sense signal.

 

Right-clicking over certain settings will provide a menu of additional options.