If we relied on dogs to do the hearing and smelling, they evidently relied on us to do some of their thinking.
We all know people treat their dogs like children, but do dogs think of humans as parents?

Today, dogs are a fixture in almost 50% of American households. In the 30,000 years humans and dogs have lived together, man's best friend has only become a more popular and beloved pet. When humans ourselves left the state of nature, our alliance with dogs might well have been dissolved.
What Dogs Do for Humans Companionship is perhaps the most obvious thing that dogs give us, but this is only the beginning. Regardless of how it all started, the human-canine bond has blossomed and strengthened over time and will likely continue to grow. Scientists believe so.