Most acute sounds are , and most coronals are acute. Rather, first are velar consonants, then coronals, labials, sibilants, etc. Lenition is blocked in these constructions if two coronals are adjacent. The laminal coronals are denti-alveolar, whereas the apicals are alveolar tending toward post-alveolar. In Australian Aboriginal languages, coronals contrast with peripheral consonants. Coronals are unique as a group in that every manner of articulation is attested. Coronals have another dimension, grooved, to make sibilants in combination with the orientations above.