Human and canine senses compared – part 2 (hearing)
This is the second article, in a series of five that will compare the five senses that humans and dogs have in common.
Hearing and the difference between a dog's hearing range and the human hearing range is explored in this article.
Human hearing – Our ears are placed laterally and cannot move independently. Our cerebral cortex decodes the sound waves captured by our outer ear and carried along the middle and inner ear to the auditory nerve, and transforms them into identifiable sounds. We can localize a specific sound somewhere in the environment, but will no longer be able to do so if we loose our sense of hearing in one of our ears. Our brain is less devoted to sound than it is to vision, which places us at a disadvantage when we compare our hearing abilities to a dog’s hearing abilities. We detect more or less the same amount of low pitched sounds as dogs, but not nearly as many high pitched sounds, which renders our hearing less acute. The human hearing range is from 20cps (or 20Hz) up to 20,000cps (or 20kHz) and we cannot hear over as great a distance as dogs can.
Dog’s hearing – The ear’s most important function is hearing, but it is also an important organ of balance. Some dogs have erect ear flaps and others have long, floppy ones. Hearing ability is superior in dogs with erect ears, which act as amplifiers for incoming sounds, and in those who can swivel their ears in the direction of the sound. Dogs can hear sounds over a wider range of frequencies and a greater distance than man. They may find high pitched noises, such as the ones emitted by vacuum cleaners and other household appliances, uncomfortable or even painful. Worth bearing that in mind with respect to dog care. According to Dr. Bruce Fogle, the range of hearing for dogs is 40,000cps (or 40kHz). They are better than us at detecting higher notes, and have the ability to move their ears independently, so that one ear can locate the sound and both ears can then catch the maximum number of sound waves. This is how dogs are endowed with the ability to hear over a greater distance than us. Many people have also wondered why dogs can hear a whistle that apears silent to humans. This is simply because dogs can hear at frequencies higher than the human hearing range, which stops, as previously stated, at around 20kHz. If the pitch of a dog whistle is set above that frequency then a dog will be able to hear it where a human will not. There are some sources that state a dog's hearing range goes from 40cps (40Hz) to 60,000cps (60 kHz), so plenty of scope to find a frequency outside of the human hearing range. Smell (or olfaction) is the sense that we’ll be comparing in the next article. Alexandra Santos Canine behaviour consultant, dog book author and trainer