A voiceless alveolar implosive is a rare consonantal sound, used in some spokenlanguages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɗ̥ ⟩ or ⟨tʼ↓⟩. A dedicated IPA letter, ⟨ƭ⟩, was withdrawn in 1993.
Its manner of articulation is occlusive, which means it is produced by obstructing airflow in the vocal tract. Since the consonant is also oral, with no nasal outlet, the airflow is blocked entirely, and the consonant is a plosive.
Its phonation is voiceless, which means it is produced without vibrations of the vocal cords.
It is an oral consonant, which means air is allowed to escape through the mouth only.
It is a central consonant, which means it is produced by directing the airstream along the center of the tongue, rather than to the sides.
The airstream mechanism is implosive (glottalic ingressive), which means it is produced by pulling air in by pumping the glottis downward. As it is voiceless, the glottis is completely closed, and there is no pulmonic airstream at all.
Mc Laughlin, Fiona (2005), "Voiceless implosives in Seereer-Siin", Journal of the International Phonetic Association, 35 (2): 201–214, doi:10.1017/S0025100305002215, S2CID145717014
