“But they covered their ears, shouting out with a loud voice, and rushed at him with one intent.”
The Jews refused to hear Stephen’s sermon which exposed their sins and challenged them to repent. They drowned him out with their shouting and stopped him by stoning him.
What the Jews did literally, covering their ears, we sometimes do figuratively. The command to hear urges us to welcome the word of God. Willingness to listen is the important first step to salvation.