In fact, its hinted that the Apostles stayed silent during the speaking.
Not really. Quite the opposite. Please note carefully:
And when they were come in, they went up into an upper room, where abode both Peter, and James, and John, and Andrew, Philip, and Thomas, Bartholomew, and Matthew, James the son of Alphaeus, and Simon Zelotes, and Judas the brother of James. These all continued with one accord in prayer and supplication, with the women, and Mary the mother of Jesus, and with his brethren... And when the day of Pentecost was fully come, they were all with one accord in one place. And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. And they were all filled with the Holy Ghost, and began to speak with other tongues [languages], as the Spirit gave them utterance. (Acts 1:13; 2:1-4)
What do we see in this passage?
1. Eleven apostles are listed (Judas Iscariot excluded)
2. "These all continued" refers to all the eleven apostles gathered there.
3. "They were all with one accord in one place" refers to the apostles as well as "the women, and Mary the mother of Jesus, and with his brethren".
4. "They were all filled with the Holy Ghost" refers to those who were "all with one accord in one place" --
the whole company including the apostles.
5. "Other tongues" means languages
other than those spoken by these Galileans.
6. "As the Spirit gave them utterance" means FOREIGN languages spoken SUPERNATURALLY.
The languages and/or dialects are all listed for us so that there is absolutely no doubt that men who normally spoke Aramaic could supernaturally speak:
1. Parthian [Arsacid Pahlavi from northwestern Iran (Persia)]
2. Medes [old Persian from western Iran (Persia)]
3. Elamites [old Persian from southwestern Iran (Persia)]
4. Mesopotamian (Akkadian or Sumerian)
5. Judaea (Hebrew)
6. Cappodocian Greek
7. Pontic Greek
8. Asia (Hittite, Luvian, Palaic, Lycian, Lydian, Carian, Phrygian, Hurrian, Urartian, Classical Armenian)
9. Phrygian Greek
10. Pamphylian Greek
11. Egyptian
12. Libyan (near the city of Cyrene)
13. Latin and official Greek
14. Minoan or Cretan Greek
15. Arabian
As we can see those languages/dialects were anywhere from 15-25. And there were probably 25 people in that company in the upper room.