Lisp

Lisp Sleepy-Time DSP is available for free download. It is part of the Sleepy-Time DSP plugins, which also include MonoChannel, StereoChannel, Crosstalk2, Transient, and DualPanner. The Lisp plugin is available in both 32-bit and 64-bit VST plugin format.

Lisp Sleepy-Time DSP is a Level-Independent Sibilance Processor (LISP), designed to speed up the process of de-essing. It uses an automatic sibilance detection algorithm to find and lower any hissing sounds in your audio by tracking both the amplitude and pitch of its input.

This allows the plugin to work regardless of the input level, providing highly transparent results. The plugin comes with a host of controls, including reduction, attack, release, stereo mode, sensitivity, sibilant range, and processing mode.

You simply set the reduction amount and let Lisp do the rest. The plugin generates an inverted copy of the signal to reduce its loudness, a simplistic concept but with very effective results.

Lisp also offers advanced stereo processing.