What is a De-Esser?

A de-esser is an audio processing tool used in recording and mixing to reduce excessive sibilance, which refers to harsh “s,” “sh,” or “ch” sounds that often occur in vocal recordings. These sounds typically appear in the higher frequency range and can become distracting or unpleasant in a mix.

A de-esser works by detecting when these high-frequency sibilant sounds become too loud and automatically reducing their level. It functions similarly to a specialized compressor that targets only a narrow band of high frequencies rather than the entire audio signal.

De-essers are commonly applied to vocal tracks during mixing to smooth out harsh consonants while keeping the vocal clear and natural. They are also sometimes used on other instruments, such as cymbals or bright guitars, when sharp high-frequency sounds need to be controlled.