From the following excerpt from Adi Parva, it is clear that there exist multiple languages during Mahabharata times
When the city was built, there came, O king, numerous Brahmanas well-acquainted with all the Vedas and conversant with every language, wishing to dwell there. And there came also unto that town numerous merchants from every direction, in the hope of earning wealth. There also came numerous persons well-skilled in all the arts, wishing to take up their abode there.
Along with that, there is also a mention of foreign language in a conversation between Vidura and Yudhishtira.
Are there any further mentions in any scriptures related to the names of the languages of those times or any other details regarding the other languages used by people?