DeSibilator is a modification to an existing DeEsser tool. DeEsser and DeClicker were offered as free plugins, but DeEsser could have odd tonal problems and didn’t always sound right. Once the design problems were identified, they were cured with DeSibilator.
https://forum.audacityteam.org/t/updated-de-clicker-and-new-de-esser-for-speech/34283/199
Koz