On my new Canon 70d I am trying to take videos in relatively quiet environments (like empty apartments). But I get this loud

Loud what? It's better to put the question in the body of the post instead of the header. Are you using an external mic when you record? Is anything running like air conditioning or heat or a refrigerator or anything else for that matter. A camera mic often picks up noises that the human ear is accustomed to or just doesn't hear.