A voiceless palato-alveolar sibilant affricate or voiceless domed postalveolar sibilant affricate is a type of consonantal sound used in some spoken languages. It is familiar to English-speakers as the "ch" sound in "chip".
This sound is transcribed in the International Phonetic Alphabet with , , , or, in broad transcription, . There is also a ligature , which was retired by the International Phonetic Association but is still used. An alternative commonly used in Americanist tradition is .
Historically, often derives from a former voiceless velar stop (as in English church; also in Gulf Arabic, Slavic languages, Indo-Iranian languages and Romance languages), or a voiceless dental stop by way of palatalization, especially next to a front vowel (as in English nature; also in Amharic, Portuguese, some accents of Egyptian, etc.).
Features of a voiceless domed postalveolar affricate:
Mandarin Chinese, Russian, Japanese, Korean, Mongolian, Polish, Catalan, and Thai have a voiceless alveolo-palatal affricate ; this is technically postalveolar but it is less precise to use .
There are several Unicode characters based on the tesh digraph (ç):