Implosive consonants are glottalic ingressive consonants, meaning that air is sucked into the mouth while pronouncing them rather than expelled out of the mouth via the lungs as in pulmonic consonants. This is accomplished by making a closure in the vocal tract (using lips, tongue or other articulators), and then lowering the glottis. For voiced sounds, it is partially closed; while for unvoiced it is completely closed. This decreases pressure in the vocal tract. The initial closure is then opened, sucking air into the mouth and producing a muffled sound.

The vast majority of implosive consonants are voiced. Implosive consonants are particularly frequent among African languages.