DID PAUL'S COMPANIONS HEAR JESUS' VOICE?

Acts 9:7 And the men which journeyed with him stood speechless, hearing a voice, but seeing no man. (KJV) Acts 22:9 (Paul speaking) And they that were with me saw indeed the light, and were afraid; but they heard not the voice of him that spake to me. (KJV)

There are two possible answers to this one. The first is that in the 22:9 passage, Paul was mistaken when he said that the companions didn't hear Jesus' voice.  The author here, Luke, is merely recording that Paul said this, so this would not be considered an error unless it's true that Paul never said this.  If Paul said this, but was wrong, then this is an error on Paul's part, not the Bible's. But besides that, the Greek word used, 'akouo', just like the English word 'hear', can mean both 'to perceive sound' and 'to understand what is said'.  So it's probable that they perceived the sound of the voice, but did not understand what it was saying, which contradicts neither passage.  In fact, both the NIV and NAS versions translate the highlighted parts of Acts 22:9 as saying  they 'did not understand the voice'. Not a contradiction.