Sibilant

Sibilants (from Latin: sibilans'hissing') are fricative and affricate consonants of higher amplitude and pitch, produced with a high velocity jet of air going on to strike the edge of some obstruction, such as the teeth and sometimes the lips. Examples of sibilants in English are the consonants at the beginning of words sip, zip, ship, and genre. The symbols in the International Phonetic Alphabet used to denote the sibilant sounds in these words are, respectively, [s,z,ʃ,ʒ]. 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!").