Scripture: Acts 26:12-18, Col 1:13, etc.
On one of these journeys I was going to Damascus with the authority and commission of the chief priests. About noon, O king, as I was on the road, I saw a light from heaven, brighter than the sun, blazing around me and my companions. We all fell to the ground, and I heard a voice saying to me in Aramaic (Acts 26:12-14),
Please pay close attention to these words of Paul describing his experience. He says that he first saw a light from heaven (sky) that shone around him and his companions. He also says that because of the light, not only he but also his companions fell, indicating that it was not a vision, but was happening at that time. Then he heard a voice in Aramaic, saying:
Saul, Saul, why do you persecute me?
It is hard for you to kick against the goads (v. 14).
In ch. 9, Luke also writes the following about this voice:
The men traveling with Saul stood there speechless; they heard the sound but did not see anyone (9:7).
Concerning this sound, Paul also says in ch. 22:
My companions saw the light, but they did not understand the voice of him who was speaking to me (22:9).