This is actually a feature called "top game". You can turn this off by accessing your live chess settings.
To do this, go to live chess, then in the upper right hand corner or directly below the chat box, click "settings". Then, in the box that opens go to the "play" tab and disable the "watch top game at startup" option. (Don't forget to hit the orange save button)
This should fix your issue.
I think the interface is buggy. When I go to start a new game I automatically see some one elses speed game and hear its sound effects all through my own game. This is very annoying. It is also invariably a poorly played blitz game in which they move every couple seconds so the sounds are nearly non stop distracting.