Implosive consonants are stops (and possibly affricates) with a mixed glottalic ingressive and pulmonic egressive airstream mechanism. That is, the airstream is controlled by moving the glottis downward in addition to expelling air from the lungs. Therefore, unlike the purely glottalic ejective consonants, implosives can be modified by phonation. Contrastive implosives are found in approximately 13% of the world's languages.