[zadok]

"Assuming this account is true (and I don't dispute it) this sounds more like the biblical gift than much of the ecstatic speech around today."

I agree. The gift of tongues as illustrated in Acts chapter 2 is not babble, but rather a language that each hearer hears in his own language and dialect.

[Quix]

Inferences can be made based on the root words and their root meanings.

However, a plausible case has been made that the miracle occurred in the hearer's ears.

I've heard of both types in our era. In one case where a person was preaching or praying or some such and lapsed into tongues--one speaker--and different people from different people-groups heard the speaker all in their own languages.

I've found God likes to jangle our sensibilities and surprise us often. He did throughout the Bible.