AudioSuite Processing : AudioSuite Window Footer : Reverse Button
 
Reverse Button
Pro Tools provides a Reverse button in the AudioSuite plug-in window footer for Reverb and Delay plug-ins. This lets you easily render reverse delay and reverb effects with a single click. Clicking the Reverse button provides three processes in one:
First, it reverses the Edit selection.
Then, it processes the reversed Edit selection with the current plug-in settings.
Finally, it reverses the processed Edit selection.