Vowels and nasal consonants are sonorant. The point of articulation is the position of maximum constriction in the oral cavity. Point of articulation is given by naming the lower and the upper articulators . English Consonant Points of Articulation Manner of Articulation Manner of articulation refers to the degree of constriction in the oral cavity. Obstruent consonants are made with closure sufficient to preclude spontaneous voicing.
Sonorant consonants have a vocal track open sufficiently to sustain spontaneous voicing.
A stop has a closed oral cavity. A fricative involves a narrow oral opening that results in turbulent airflow. A lateral involves an opening on the side of the mouth. A rhotic involves a retroflexed tongue tip. Both a flap and a tap involve the tongue tip.