I'm not sure if I'm on the right track, but in my experience, it's normal for the stereo to get louder when I'm closer to it. If I zoom the camera up or move to the back yard or something, the volume decreases. Then when I focus the camera back in the room that has the stereo, the volume comes back up. To me, this is normal because in real life, the stereo would sound louder if you're right in the room with it.