http://www.slate.com/articles/health_and_science/science/2015/10/vestigial_muscles_try_to_pivot_your_ears_like_a_dog_or_cat_does.html

Pet owners, you know the look: Your cat hears you pouring the Purina, and suddenly she’s all ears. As she stops in her tracks and turns to face you, her ears swivel straight toward the sound of all those salmon-flavored bits cascading into the bowl. This is your cat’s listening face, all senses trained on the all-important event happening before her. Feed me. Right. Meow.