Implosive consonants are stops (rarely 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, which is almost universally voiced. Contrastive implosives are found in approximately 13% of the world's languages.
In the International Phonetic Alphabet, implosives are indicated by modifying a voiced stop letter with a hook top: ⟨ɓ ɗ ʄ ɠ ʛ ⟩.