The De-esser is a specialized dynamics processor designed to attenuate excessive sibilance in vocal recordings. Sibilance consists of the high-frequency, sharp, and penetrating sounds produced by sibilant consonants such as S, Z, Ch, and Sh, which often become exaggerated after equalization and compression processes.

The De-esser works by using a selective compressor that acts only on a specific frequency range, usually located between 5 kHz and 10 kHz. The device monitors this region of the spectrum and, when the intensity of the sibilant frequencies exceeds a defined limit (threshold), it applies a quick and momentary gain reduction. This allows you to control the harshness and high-pitched peaks of the voice without altering the volume or timbre of other parts of the vocal performance.