7.2.2 Consonants: Place of Articulation

Because consonants are made by restricting the airflow in some way, consonants can be distinguished by where this restriction is made: the point of maximum restriction is called the place of articulation of a consonant. Places of articulation, shown in Fig. 7.4, are often used in automatic speech recognition as a useful way of grouping phones together into equivalence classes:

labial: Consonants whose main restriction is formed by the two lips coming together have a bilabial place of articulation. In English these include [p] as in $ \underline{p} $ossum, [b] as in $ \underline{h} $ear, and [m] as in $ \underline{m} $armot. The English labiodental consonants [v] and [f] are made by pressing the bottom lip against the upper row of teeth and letting the air flow through the space in the upper teeth.

dental: Sounds that are made by placing the tongue against the teeth are dentals. The main dentals in English are the [th] of $ \underline{\text{thing}} $ or the [dh] of $ \underline{\text{though}} $, which are

made by placing the tongue behind the teeth with the tip slightly between the teeth.

alveolar: The alveolar ridge is the portion of the roof of the mouth just behind the upper teeth. Most speakers of American English make the phones [s], [z], [t], and [d] by placing the tip of the tongue against the alveolar ridge. The word coronal is often used to refer to both dental and alveolar.

palatal: The roof of the mouth (the palate) rises sharply from the back of the alveolar ridge. The palato-alveolar sounds [sh] (shrimp), [ch] (china), [zh] (Asian), and [jh] (jar) are made with the blade of the tongue against this rising back of the alveolar ridge. The palatal sound [y] of $ \underline{y} $ak is made by placing the front of the tongue up close to the palate.

velar: The velum or soft palate is a movable muscular flap at the very back of the roof of the mouth. The sounds [k] (cu $ \underline{ck} $oo), [g] (g $ \underline{o} $ose), and [ŋ] (k $ \underline{ing} $fisher) are made by pressing the back of the tongue up against the velum.

glottal: The glottal stop [q] (IPA [ʔ]) is made by closing the glottis (by bringing the vocal folds together).