The voiceless post-alveolar affricate is a sound used in some spoken languages. It is in English and is written as ch or tch, as in chat and match. The sound is made by starting with /t̠/ and following it with /ʃ/.
Characteristics
The phonation is voiceless. This means that this sound is produced without vibrations of the vocal cords. In some languages the vocal cords are actively separated, so it is always voiceless; in others the cords are lax, so that it may take on the voicing of adjacent sounds.
The place of articulation (where the sound is produced) is palato-alveolar, that is, domed (partially palatalized) postalveolar. This means that this sound is produced with the blade of the tongue behind the alveolar ridge, and the front of the tongue bunched up ("domed") at the palate.
The manner of articulation (how the sound is produced) is affricate. This means that this sound is produced by first stopping the air flowing from the mouth, then allowing air flow through a constricted channel at the place this sound is produced, to make turbulence.
