according to historian ram sharan sharma in his book india's ancient past mentioned that, many austroasiatic, dravidian, and non-sanskrit terms occur in the vedic texts ascribed to 1500-500 bc.they indicate ideas, institutions, products, and settlements associated with peninsular and non-vedic india. the people of this area spoke the proto-munda language. several terms in the indo-aryan languages that signify the use of cotton, navigation, digging, stick, etc. have been traced to the munda languages by linguists. there are many munda pockets in chota nagpur plateau, in which the remnants of munda culture are strong. it is held that changes in the phonetics and vocabulary of the vedic language can be explained as much on the basis of the dravidian influence as that of the munda.