Acts 2:2-6

and suddenly a sound came from heaven like a rushing violent wind, and it filled the whole house where they were sitting. There appeared to them tongues resembling fire, which were being distributed [among them], and they rested on each one of them [as each person received the Holy Spirit]. And they were all filled [that is, diffused throughout their being] with the Holy Spirit and began to speak in other tongues (different languages), as the Spirit was giving them the ability to speak out [clearly and appropriately]. Now there were Jews living in Jerusalem, devout and God-fearing men from every nation under heaven. And when this sound was heard, a crowd gathered, and they were bewildered because each one was hearing those in the upper room speaking in his own language or dialect.