Lina01 lecture 4 (chapter 6) : phonology the sound patterns of. Natural classes: are set of sounds that have a similar pattern. Sounds that have the same features in the same row (manner) or column (place) or voicing are examples of natural classes. For example: [p, t, k] are voiceless stops. Natural class is applied to both consonants and vowels. The pronunciation of some natural classes are affected in the presence of other natural classes. They obstruct the airflow in the oral cavity. Continuants: when there is a continuous flow of air out of the mouth. This is for all other consonants and all vowels. This is when the air flow is fully or partially blocked. They have a free flow of air and have a greater acoustic energy. They involve the lips in order to be articulated. The blade of the tongue is raised to hard palate or the alveolar ridge. Anteriors: are bilabials, labiodentals, interdentals, and alveolars.