well, understand that the tongues themselves DID NOT cause the crowds to turn to God. The tongue-speaking did turn the crowd to God, but it was together with Peter's speech that salvation was chosen by them. Besides, there is no evidence in the Bible for a "spiritual tongue". Paul's reference to the "tongue of angels" in 1 Corinthians was a hyperbolic reference to the impossible. Neither is there evidence for latter tongues or latter gifts. If you go check out 1 Cor 14, all gifts aren't meant for self-edification at all (although they do bring about that simply coz of their nature). They're given solely to build up the Body.