John Calvin Commentary Acts 22:9

"And they that were with me beheld indeed the light, but they heard not the voice of him that spake to me." — Acts 22:9 (ASV)

They who were with me. I showed elsewhere that there is no such disagreement in Luke's words as there seems to be. Luke said there that, although Paul’s companions stood amazed, they still heard a voice. But in this passage, he says they did not hear the voice of the one who spoke to Paul, although they saw the light.

Surely, it is not absurd to say that they heard some obscure voice, yet in such a way that they did not discern it as Paul himself did—Paul, whom alone Christ intended to stop and subdue with the rebuke.

Therefore, they hear a voice because a sound enters their ears, so they know that someone is speaking from heaven; they do not hear the voice of the one who spoke to Paul because they do not understand what Christ says. Moreover, they see Paul surrounded by the light, but they see no one speaking from heaven.