Now there were Jews living in Jerusalem, devout men from every nation under heaven. And when this sound occurred, the crowd came together, and were bewildered because each one of them was hearing them speak in his own language. They were amazed and astonished, saying, "Why, are not all these who are speaking Galileans? And how is it that we each hear them in our own language to which we were born? Parthians and Medes and Elamites, and residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia, Phrygia and Pamphylia, Egypt and the districts of Libya around Cyrene, and visitors from Rome, both Jews and proselytes, Cretans and Arabs-we hear them in our own tongues speaking of the mighty deeds of God." And they all continued in amazement and great perplexity, saying to one another, "What does this mean?"
Acts 2:5-12 NASB
I think some folks like to spend more time on the method of speaking, than what was the significance of the event. Speaking of the mighty deeds of God, and we all hear it in our native languages.
Why is this happening?
but this is what was spoken of through the prophet Joel: ' And it shall be in the last days ,' God says, ' that I will pour forth of My spirit on all mankind ; and your sons and your daughters shall prophesy , and your young men shall see visions , and your old men shall dream dreams ; Even on my bondslaves, both men and women , I will in those days pour forth of My spirit And they shall prophesy. ' And I will grant wonders in the sky above and signs on the earth below , blood, and fire, and vapor of smoke . ' The sun will be turned into darkness and the moon into blood , before the great and glorious day of the Lord shall come . ' And it shall be that everyone who calls on the name of the Lord will be saved .' "Men of Israel, listen to these words: Jesus the Nazarene, a man attested to you by God with miracles and wonders and signs which God performed through Him in your midst, just as you yourselves know- this Man, delivered over by the predetermined plan and foreknowledge of God, you nailed to a cross by the hands of godless men and put Him to death. But God raised Him up again, putting an end to the agony of death, since it was impossible for Him to be held in its power.
Acts 2:16-24 NASB
Why do we like to get caught up in ambiguous statements about how rather than what it means? They spoke in other tongues as the spirit gave utterance, rather than what was said? They testified to the mighty deeds of God.
They spoke as the spirit gave utterance, who cares what languages or babblings that was? What matters is what was really happening.
They were speaking of the mighty works of God, and that men of all nation's witnessed by the power of the holy spirit poured out in that day.
You know God opened the mouth of a jackass to speak to Balaam. It wouldn't surprise me to find a church group sitting in pastures waiting for livestock to speak to them. Is it jackasses only or any equine?
The point is the Holy Spirit gave utterance. God opened the mouths and ears.