The voiceless or more precisely tenuis lateral click is a click consonant found primarily among the languages of southern Africa. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ǁ⟩. The Doke/Beach convention, adopted for a time by the IPA and still preferred by some linguists, is ⟨ʖ⟩.
The airstream mechanism is lingual ingressive (also known as velaric ingressive), which means a pocket of air trapped between two closures is rarefied by a "sucking" action of the tongue, rather than being moved by the glottis or the lungs/diaphragm. The release of the forward closure produces the "click" sound. Voiced and nasal clicks have a simultaneous pulmonic egressive airstream.
Its phonation is voiceless, unaspirated, and unglottalized, which means it is produced without vibration or constriction of the vocal cords, and any following vowel starts without significant delay.
It is an oral consonant, which means air is allowed to escape through the mouth only.
It is a lateral consonant, which means it is produced by directing the airstream over the sides of the tongue, rather than down the middle.