DENTAL

In most English sounds, and most speech sounds in general, the active articulator is part of the tongue; to avoid confusion, places of articulation where the tongue is involved are therefore generally called after the passive articulator. For the two dental fricatives, it follows that the passive articulator is the top front teeth; the active articulator is the tip of the tongue. The tongue itself is conventionally divided into the tip (the very front); the blade (just behind the blade, and lying opposite the alveolar ridge); the front (just behind the blade, and lying opposite the hard palate); the back (behind the front, and lying opposite the velum); and the root (right at the base, lying opposite the wall of the pharynx).