Phonology
Dravidian languages are noted for the lack of distinction between aspirated and unaspirated stops. While some Dravidian languages have accepted large numbers of loan words from Sanskrit and other Indo-Iranian languages in addition to their already vast vocabulary, in which the orthography shows distinctions in voice and aspiration, the words are pronounced in Dravidian according to different rules of phonology and phonotactics: aspiration of plosives is generally absent, regardless of the spelling of the word. This is not a universal phenomenon and is generally avoided in formal or careful speech, especially when reciting.
For instance, Tamil does not distinguish between voiced and voiceless stops. In fact, the Tamil alphabet lacks symbols for voiced and aspirated stops.
Dravidian languages are also characterized by a three-way distinction between dental, alveolar, and retroflex places of articulation as well as large numbers of liquids.
Read more about this topic: Dravidian Languages