The most photogenic, heartwarming, smile-generating canine pose…the head tilt. Dog owners are entertained by the upward turned face, curious eyes, and perky ears that accompany the cute head tilt when their dog hears an interesting sound.
Why do dogs tilt their heads when they hear a strange sound?
Dogs have a keener sense of hearing than people do and can detect frequencies and sounds that escape us. But humans have an advantage over dogs in one regard: a person with normal hearing ability can detect a sound regardless of the direction from which it is initiated, while a dog’s directional hearing is more limited.
The external human ear is engineered to pick up sound so efficiently that a person does not have to turn toward the sound to capture it. A person’s ability to discern sound is not affected by whether it comes from the front, back, left, or right so when someone calls you from behind, you do not have to pivot to hear him.
Not so with dogs. Dogs have ear flaps that partially or completely cover the ear canal and serve as a barrier to sound transmission, so dogs must change their position to optimize sound detection. Luckily, the canine ear flap (pinna) is movable so the dog can make the necessary adjustment needed to focus on the exact location of the sound.
Different breeds face different challenges. A German Shepherd’s ear flap covers only the back side of the canal and limits the detection of sounds from the rear. A Spaniel has heavy ear flaps that entirely cover the ear canals and interfere with sound wave transmission from all directions.
How does head-tilting help with hearing?
To compensate for the interference of ear flaps, dogs perk up their pinnae and tilt their heads for optimum sound collection. If an interesting sound comes from the front, a dog tilt its head in the direction of the sound. If the sound comes from the rear, the dog may turn before tilting his head.
If a sound comes from the side, he may not tilt at all because canine ears are located on the sides of the head and are already in a good position to pick up the sound waves.
Movable ear flaps also help a dog judge a sound’s distance by determining the time difference between when the sound reaches the right versus left ear. Essentially, tilting the head and adjusting ear flaps helps the dog assess the location and distance of sound.