Yes, it's against Big 12 (and NCAA) rules for a home team to pump artificial crowd noise through the speakers during play. Artificial noise, including pre-recorded crowd sounds, is typically prohibited while the play clock is running. However, teams can play music, announcements, and other sounds during breaks, such as timeouts, halftime, and in between plays, to keep the crowd engaged.
If a team is caught using artificial noise during the game, they may face penalties, fines, or other disciplinary actions. This rule is in place to ensure a fair playing environment and that the crowd noise reflects genuine fan engagement.