This does ot say 'a heavenly language'. It does say 'other tongues according as the Spirit was giving them. We should not presume then that Peter spoke in a Heavenly tongue.
Imagine the scene: "each one hearing them speaking in his proper dialect" ... aside from the confusion it must have appeared, so many languages and dialects all spoken at the same time, yet each man heard the one dialect he understood out of all the noise of so many dialects being spoken simultaneously by those believers.
From a little distance, such a conglomeration of various dialects being uttered passionately and simultaneously, with hands raised to the heavens (??) it must have sounded like a couple of dozen of hysterical drunks. Eh?
Hey, M, looking back all through the OT and the NT, did you ever hear of an angel speak to a human in a tongue not understood by both? Well, if that's so, any "tongue" sound that is not a language but just as someone speaking without any agape love in his/her heart, wouldn't you say?
But then, I have no degree in babbelology, so what can I say?
I wonder if anyone heard in Tagalog, or Cebuano? 😁