In
phonetics, an egressive sound is one where
air flows outward. Er... isn't that all of them, he asked him knowingly? Not quite. Almost every sound in every language is egressive, but
Bantu and other African families have some sounds that are
implosive (q.v. for more detail) and the
Khoe (or
Khoisan) languages of southern Africa have their famous
clicks. When speaking, whatever the language, most of the time air is being pushed out from the
lungs, and
interruptions to it are of short duration.
As well as the normal pulmonic air stream, certain specially emphatic egressive sounds can be made by compressing the air in the mouth and releasing it explosively: see ejective for details and examples.