sibilation

noun

The act of sibilating or hissing; the utterance or emission of sibilant sounds; also, a hissing sound; in style, predominance or prominence of the sound of s.

Utterance with a hissing sound; also, the sound itself; a hiss.

A hissing sound.

Pronunciation with a sibilant (hissing or whistling) sound.

A fricative sound (especially as an expression of disapproval).