Sibilation

n.

1.

Utterance with a hissing sound; also, the sound itself; a hiss. He, with a long, low sibilation, stared. - Tennyson.

Noun	1.	sibilation - a fricative sound (especially as an expression of disapproval); "the performers could not be heard over the hissing of the audience" Synonyms: hiss, hissing
	2.	sibilation - pronunciation with a sibilant (hissing or whistling) sound Synonyms: assibilation

aphonia, artificial voice, broken speech, broken tones, broken voice, childish treble, choked voice, cracked voice, croak, crow, dysarthria, dyslalia, dyslogia, dysphasia, dysphonia, dysphrasia, falsetto, harshness, hawking voice, hiss, hoarseness, idioglossia, idiolalia, impairment of speech, lisp, lisping, loss of voice, muzzy speech, nasal tone, nasalization, quaver, shake, speech defect, speech impediment, tremor, twang