Voiceless sibilant

Sibilance is a manner of articulation of fricative and affricate consonants, made by directing a stream of air with the tongue towards the sharp edge of the teeth, which are held close together; a consonant that uses sibilance may be called a sibilant, or a strident. Examples of sibilants are the consonants at the beginning of the English words sip, zip, ship, chip, and jump, and the second consonant in vision. The symbols in the International Phonetic Alphabet used to denote the sibilant sounds in these words are, respectively, [s] [z] [ʃ] [tʃ] [dʒ] [ʒ]. More specifically, the sounds [tʃ] [dʒ], as in chip and jump, are affricates, whereas the rest are fricatives. Sibilants have a characteristically intense sound, which accounts for their paralinguistic use in getting one's attention (e.g. calling someone using "psst!" or quieting someone using "shhhh!").

In the alveolar hissing sibilants [s] and [z], the back of the tongue forms a narrow channel (is grooved) to focus the stream of air more intensely, resulting in a high pitch. With the hushing sibilants (occasionally termed shibilants), such as English [ʃ], [tʃ], [ʒ], and [dʒ], the tongue is flatter, and the resulting pitch lower.

Because all sibilants are also stridents, the terms are sometimes used interchangeably. However, the terms do not mean the same thing. The English stridents are /f, v, s, z, ʃ, ʒ, tʃ, dʒ/. The English sibilants are a more high pitched subset of the stridents. The English sibilants are /s, z, ʃ, ʒ, tʃ, dʒ/. /f/ and /v/ are stridents, but not sibilants, because they are lower in pitch.

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