The Anatomy of a Dog's Ear

Dogs depend on their hearing much more than humans and for good reason--they hear better than we do. The anatomy of a dog's ear allows greater sensitivity to a wider frequency of sound, a fact that has helped their survival for thousands of years. But that anatomy does not keep a dog from having ear problems. Breeds with floppy ears and dogs who spend a lot of time in the water can contract infections and damage their hearing despite nature's preventative design.

  1. Ear flap

    • The outer ear's primary part is the pinna or ear flap, which may be floppy, upright or pointed. The pinna is made of cartilage, skin and hair, capable of a vast amount of movement to adjust for better auditory angles as well as to transmit social cues to others in the dog's pack.

    Ear canals

    • Unlike humans, dogs have two types of ear canals. The vertical ear canal descends into the horizontal ear canal, positioned exactly as the names imply. Cerumen lines the horizontal canal, a waxy substance that repels water. The two sets of canals and cerumen in the horizontal canal protect the dog's ear from the water retention that can infect and damage the ear. A thin layer called the tympanic membrane separates the outer ear ending at the horizontal ear canal canals from the tympanic cavity, or middle ear.

    Middle ear

    • The tympanic cavity contains bones or ossicles that vibrate when sound waves hit them. The bulla is also in the middle ear, a cavity lined with a membrane and filled with air that detects the lower registers of sound. The Eustachian tube leads from the bulla to the back of the mouth.

    Inner ear

    • This part of the ear is fluid filled, which helps transmit the sound frequencies to the correct nerves. The inner ear contains all the nerves that receive the sound waves for transmitting to the brain. It is also responsible transmitting the necessary information to the brain for maintaining balance.

    Expert Insight

    • Because of the anatomy of a dog's ear, their hearing is better than human hearing. Humans can hear a range of 64 to 23,000 Hertz, and dogs can hear from a range of 67 to 45,000 Hertz. The higher the Hertz means the higher the frequency, which is why dogs can hear a dog whistle while humans hear nothing. This is also why loud, high-pitch noises such as fire trucks and tornado warnings cause dogs to bark or howl--it hurts their ears.