Acts 9:7 (KJV)
And the men which journeyed with him stood speechless, hearing a voice, but seeing no man.
Acts 22:9 (KJV - see also ESV)
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.
We all fell to the ground, and I heard a voice saying to me in Aramaic, "Saul, Saul, why do you persecute me? It is hard for you to kick against the goads."