Most animals don't use verbal communication. As an analogy, most humans don't use sign language. Imagine if someone wanted to create a human translator that recorded what humans do with their hands and translate them into meaning. There would be a lot of noise there because most humans don't talk with their hands, so most of it would be ascribing meaning that isn't there. Sometimes the person is just itching their back, or just doing the dishes, etc, not trying to say something. Similarly, most other animals vocalise for other reasons, not because they want to make a specific sound to communicate something.