Lisp – Free Sibilance Processor VST Plugin Released By Dustin Ralston

Lisp by Dustin Ralston.

Lisp by Dustin Ralston.

Dustin Ralston (aka Sleepy-Time DSP has released) has released Lisp, a freeware de-esser in VST plugin for Windows.

Lisp (Level-Independent Sibilance Processor) is a free de-essing tool for your digital audio workstation that works regardless of the input level and requires no frequency setting.

Lisp is available for free download via Sleepy-Time DSP (1.45MB download size, 32-bit & 64-bit VST plugin format for Windows).

The plugin was designed to be more efficient than standard sibilance processors, while keeping the CPU hit low. It uses the transient detection algorithm from Sleepy-Time DSP’s Transient plugin to recognize harsh “s” sounds with higher precision.

I loved all Sleepy-Time DSP plugins released so far (they are now available for download in the STR Legacy Bundle) and I’m expecting the same from Lisp. So far, my favorite freeware de-esser has beed SPITFISH by digitalfishphones.


Download Lisp: click here

Share this article. ♥️

About Author

Tomislav is a music producer and sound designer from Belgrade, Serbia. He is also the founder and editor-in-chief at Bedroom Producers Blog.


  1. Afternoon,

    Thanks so much for your page. I was curious if you [or anyone] could assist with this specific plugin in 64 bit. I have seen it linked in several places online, but all of the links are disabled. I’ve been on the hunt for a 64 bit De Esser for a bit and would love to give this one a go.

  2. Joanna Phillips


    Hi, I can’t get the plugin to actually work in Audacity: It loads onto list of new plugins, I enable it and restart. It then doesn’t show up on effects and is under new plugins again. Any advice please? I’ve heard your plugin is great and I really want to use it!

Leave A Reply