Vowels: Proto-Dravidian had ten vowels: a, ā, e, ē, u, ū, i, ī, o, ō. There was contrast between short and long vowels. There were no diphthongs. ai and au are treated as *ay and *av (or *aw) (Subrahmanyam 1983, Zvelebil 1990, Krishnamurti 2003).
Consonants: Proto-Dravidian is reconstructible with the following consonantal phonemes (Subrahmanyam 1983:p40, Zvelebil 1990, Krishnamurti 2003) :
|  | Labial | Dental | Alveolar | Retroflex | Palatal | Velar | Glottal | 
|---|
| Plosive | p | t | ṯ | ṭ | c | k |  | 
| Nasal | m | n | ṉ (??) | ṇ | ñ |  |  | 
| Flap |  |  | r |  |  |  |  | 
| Fricative |  |  |  | ḻ (ṛ, r̤) |  |  | (H) | 
| Lateral |  |  | l | ḷ |  |  |  | 
| Approximant | v |  |  |  | y |  |  |