Is that not the cutest thing you've ever heard?
Dogs tilt their head at you because they want you to know they care. Jesus Christ, that's just the best news ever. Dogs are known for having an oddly constructed hearing apparatus that consists of an outer ear and inner ear and, in order to hear more sensitively, they sometimes tilt their head in order to hear better.
They also have to compensate for their muzzles in order to see our facial expressions and read our reactions. Dr. Stanley Coren has a few theories on the subject.
"We know that dogs continually scan our faces for information and to read our emotional state. Hence it is likely that one reason why dogs may tilt their heads when we talk to them is because they want to see our faces better, and to compensate for the way in which their muzzles obscure part of their vision," explains Dr. Coren.
"Some dogs have flatter faces. Technically they are said to have brachycephalic heads. These would include dogs like Pugs, Boston Terriers and Pekingese. With a less prominent muzzle extension, there should be a reduced amount of visual obstruction, and these dogs would need to tilt their head less."
His study found that 62% of those who took a quick survey reported that their dogs frequently to always tilted their heads when they spoke to them, indicating what we already know - dogs are empathetic by their very nature. So when you see your dog tilting his head at you, it's because they're trying to understand what you're saying and care.
Dogs are better than people, basically.