In phonetics and phonology, an alveolar stop is a type of consonantal sound, made with the tongue in contact with the alveolar ridge located just behind the teeth (hence alveolar), held tightly enough to block the passage of air (hence a stop consonant). The most common sounds are the plosives [t] and [d], as in English toe and doe. More generally, several kinds are distinguished:
Note that alveolar and dental stops are not always carefully distinguished. Acoustically, the two types of sounds are similar, and it is rare for a language to have both types.