Sound doesn't play on MacBook while Apple TV is on

Ever since I started used my Apple TV, my MacBook Pro has had some weird behaviours. While my Apple TV is on, the sound will not play on my MacBook at all (from both speakers and headsets), and sometimes will play on the Apple TV, even though nothing is on it, or not play at all. The only way to get rid of this is to mirror another device onto the Apple TV, put it to sleep, or unplug the power. Yes, I've checked System Preference > Sound, and it is all normal, all it says is Internal Speakers and Built-in. I also found that whenever I attempt to disconnect from my Apple TV, what I get is that the Apple TV is on the home screen, the sound from my MacBook continues to play on the Apple TV, and most annoying of all, the display thing on the menu bar is blue, it says I'm still connected to the Apple TV, and I can't connect. 'Extend display' is also selected and that can't be changed. When I go to System Preferences > Displays, on the Airplay Device section, it will say Apple TV, and whenever I change it to "none', it reverts back to Apple TV. Anyone know how to fix this?