One can presume, since religion is usually infinitely flexible when it comes to explaining away technicalities and mysteries, that God didn't have to talk.
Nonetheless, the literature makes it clear that the Semitic tribes who founded what eventually became Judaism and its siblings (Christianity, Islam, Baha'i and Rasta) communicated with each other (and, apparently, also with their God) by use of spoken language. Moreover, that same literature makes it clear that the language is an early form of Hebrew--one that any reasonably well-educated speaker of modern Israeli Hebrew can understand quite easily.
Hebrew is a member of the Canaanite branch of the Northwestern Semitic group, one of the six closely-related branches of the Afro-Asiatic language family. Oddly, despite the massive historical and cultural history of this language family, no one has ever been able to determine whether it originally arose in Africa or Asia. Historians all over the world would love to find out whether the original Afro-Asiatic people arose in Mesopotamia and then made the trek to northern Africa... or instead, they arose in Africa and one adventurous group emigrated to Asia, where they would establish one of the most-studied civilizations on this planet, not to mention a couple of the human race's most beloved religions.
Never mind that it would be illogical as no evidence shows that all languages descend from the Semitic family!
Indeed, the reverse is more likely true. There are hundreds of language families strewn over this planet, whose structures, vocabularies and phonetics make it almost 100% certain that they have no relation to each other.
We can go with the early Catholic church's belief on it and say God only speaks and understands Latin.
Apparently God has never had good relations with the Jews. There is plenty of evidence of Hebrew being spoken and written at least a thousand years before Latin became even slightly important.
