Are you talking about Acts 2 or the gift of interpretation of tongues?
I believe in Acts 2 that the actual languages were coming out of the mouths of the disciples. The passage says those present testified that they heard them speak in their languages, not that they heard the languages but the disciples were not speaking in them--like watching a Kung Fu movie with English dubbing.
I can of at least three accounts for Azusa Street of people present hearing and recognizing their own language and understanding the interpretation. I saw a recording of another testimony about this from that era from a meeting outside of Azusa. A number of Assembies of God missionaries have testified to such events occurring. I know of five people I can think of who can tell of other people having understood them they understood what they spoke in tongues. Make that six if that one missionary is still alive.
I haven't interpreted tongues, but from talking with people, it sounds like it comes the same way a lot of prophecies come, as a message, but one that follows a message in tongues in this case. I know people who experienced hearing a message in tongues, getting the message, but someone else gives it first. Ironically, one of these is a long time friend who has never spoken in tongues himself.