There are several reasons why you may not be able to hear a driver's radio communication playing during an event:
- Driver/team communication itself is very light and they do not talk much
- Team may not have set their radios up correctly, which means the radio providers (Racing Electronics) is not getting the feed properly
- Driver might have wrecked out of the race, or they are not out on track for any given reason
- The practice, qualifying, or race session might not have started yet, where team communication would be necessary.