The Origin Of Speaking In Tongues
After the Flood, the descendants of Noah and his wife developed their own languages, or "tongues."
"10:2 The sons of Japheth; Gomer, and Magog, and Madai, and Javan, and Tubal, and Meshech, and Tiras. 10:3 And the sons of Gomer; Ashkenaz, and Riphath, and Togarmah. 10:4 And the sons of Javan; Elishah, and Tarshish, Kittim, and Dodanim. 10:5 By these were the isles of the Gentiles divided in their lands; every one after his tongue, after their families, in their nations." (Genesis 10:2-5 KJV)
Despite the differences in "tongues" that developed, they were still, at that point, merely regional dialects of and within their single, common ancestral language (just as, for example, people who speak the wide variety of English dialects around the world can still understand each other).
"10:32 These are the families of the sons of Noah, after their generations, in their nations: and by these were the nations divided in the earth after the flood. 11:1 And the whole earth was of one language, and of one speech." (Genesis 10:32, 11:1 KJV)
"The LORD did there confound the language of all the earth"
Unintelligible and uncomprehensible tongues, that is, all of the different languages in the world today, were a creation of the LORD as a response to the united defiance of humanity toward Him.
"10:31 These are the sons of Shem, after their families, after their tongues, in their lands, after their nations. 10:32 These are the families of the sons of Noah, after their generations, in their nations: and by these were the nations divided in the earth after the flood." (Genesis 10:31-32 KJV)
Fact Finder: What is the Christian purpose of "speaking in tongues"?