Could you connect these Acts 9:7 and Acts 22:9 together? It seems they are contradicting each other.
In the two passages you mentioned (plus a third passage from Acts), Paul gives his testimony:
First, notice that Paul’s three accounts differ in small details. These differences are the normal variations that we would expect anytime someone related a story multiple times. If you tell a story about your childhood to three different people, most likely your three versions would differ at least slightly from one another.
In the case of what Paul’s companions saw and heard, Paul’s first two retellings relate the scene slightly differently though not contradictory. In Acts 9 Paul says the men heard the voice but saw “no one,” meaning they never witnessed the source of the voice. Instead, they saw only a bright light. In the second account in Acts 22 Paul repeats that the men saw the light, and he adds that they didn’t understand the voice they heard.
So these two passages are entirely consistent and complimentary. The men saw a light, as Paul said in both passages. They also heard a voice, which Paul also said in both passages, but they never saw the Person speaking and they could not understand the voice. Paul alone saw Christ and understood Christ’s words.