SilentFish alters the sound effects volume while you fish to minimize the chance you'll hear someone else's bobber splash. This makes it easier to fish in more densely populated areas (such as the Dalaran Fountain).
The addon gathers data as you fish, eventually enabling you to change the default timing to match observed results. Access the SilentFish configuration panel through the Addons tab of the Interface Options window to see the current sound timing and observed statistics.
Version 2: Fixed an issue where the sound was not muted at the start of the cast in some circumstances.
Version 3: Fixed an issue where GetSpellInfo could be called with invalid arguments.