Voiceless postalveolar fricative

IPA – number	134
IPA – text	ʃ
IPA – image
Entity	ʃ
X-SAMPA	S
Kirshenbaum	S
Sound sample (help·info)

The voiceless palato-alveolar fricative or domed postalveolar fricative (IPA [ʃ]) is a type of consonantal sound, used in some spoken languages.

The sound occurs in many languages and, as in English, French and Italian, where it may have simultaneous lip rounding ([ʃʷ]), although this is rarely indicated.

Symbol

The symbol in the International Phonetic Alphabet that represents this sound is <ʃ>, the letter esh introduced by Isaac Pitman (not to be confused with the integral sign ∫), and the equivalent X-SAMPA symbol is S. An alternative symbol used in some older and American linguistic literature is š, an s with háček, originating with the Czech alphabet of Jan Hus (also used in Gaj's Latin alphabet as well as scientific and ISO 9 transliterations of Cyrillic).

Features

Features of the voiceless postalveolar fricative:

• Its manner of articulation is sibilant fricative, which means it is produced by directing air flow through a groove in the tongue at the place of articulation and directing it over the sharp edge of the teeth, causing high-frequency turbulence.
• Its place of articulation is palato-alveolar, that is, domed (partially palatalized) postalveolar, which means it is articulated with the blade of the tongue behind the alveolar ridge, and the front of the tongue bunched up ("domed") at the palate.
• Its phonation type is voiceless, which means it is produced without vibrations of the vocal cords.
• It is an oral consonant, which means air is allowed to escape through the mouth.
• It is a central consonant, which means it is produced by allowing the airstream to flow over the middle of the tongue, rather than the sides.
• The airstream mechanism is pulmonic egressive, which means it is articulated by pushing air out of the lungs and through the vocal tract, rather than from the glottis or the mouth.

Occurrence

The sound in Russian denoted by <ш> is commonly transcribed as a postalveolar fricative but is actually a laminal retroflex fricative.

See also

• List of phonetics topics

References

Bibliography

• Cruz-Ferreira, Madalena (1995), "European Portuguese", Journal of the International Phonetic Association 25 (2): 90-94 
• Ladefoged, Peter (2005). Vowels and Consonants (Second ed.). Blackwell. 
• Merrill, Elizabeth (2008), "Tilquipan Zapotec", Journal of the International Phonetic Association 38 (1): 107-114 
• Rogers, Derek; d'Arcangeli, Luciana (2004), "Italian", Journal of the International Phonetic Association 34 (1): 117-121 
• Shosted, Ryan K.; Vakhtang, Chikovani (2006), "Standard Georgian", Journal of the International Phonetic Association 36 (2): 255-264 
• Thelwall, Robin (1990), "Illustrations of the IPA: Arabic", Journal of the International Phonetic Association 20 (2): 37-41