FYI..The cameras and microphones..the camera angles..when they are on or off, etc.. in the House and Senate are controlled by the House and Senate respectively, and NOT C-span. That's so that when, for example, "Sheets" is rambling on..you can't tell that the Senate chamber is empty..The only times that isn't true are when it's a joint session of Congress, like for the SOTU..then C-span puts more cameras in, and they control the shots and the angles..
Here's something I discovered accidentally a few years ago. I was watchig the Senate debate, late at night, on the Iraq war issues, and so as NOT to disturb the wife, I plugged my headphones into the TV..You can pick up hushed, whispered comments..that are not audible over regular TV sound speakers..I heard a muted "son of a bitch"..among others..